<?php
  
  namespace Illuminate\Support;
  
  use ArrayAccess;
  use ArrayIterator;
  use Illuminate\Support\Traits\EnumeratesValues;
  use Illuminate\Support\Traits\Macroable;
  use stdClass;
  
  class Collection implements ArrayAccess, Enumerable
  {
      use EnumeratesValues, Macroable;
  
      /**
       * The items contained in the collection.
       *
       * @var array
       */
      protected $items = [];
  
      /**
       * Create a new collection.
       *
       * @param  mixed  $items
       * @return void
       */
      public function __construct($items = [])
      {
          $this->items = $this->getArrayableItems($items);
      }
  
      /**
       * Create a new collection by invoking the callback a given amount of times.
       *
       * @param  int  $number
       * @param  callable|null  $callback
       * @return static
       */
      public static function times($number, callable $callback = null)
      {
          if ($number < 1) {
              return new static;
          }
  
          if (is_null($callback)) {
              return new static(range(1, $number));
          }
  
          return (new static(range(1, $number)))->map($callback);
      }
  
      /**
       * Get all of the items in the collection.
       *
       * @return array
       */
      public function all()
      {
          return $this->items;
      }
  
      /**
       * Get a lazy collection for the items in this collection.
       *
       * @return \Illuminate\Support\LazyCollection
       */
      public function lazy()
      {
          return new LazyCollection($this->items);
      }
  
      /**
       * Get the average value of a given key.
       *
       * @param  callable|string|null  $callback
       * @return mixed
       */
      public function avg($callback = null)
      {
          $callback = $this->valueRetriever($callback);
  
          $items = $this->map(function ($value) use ($callback) {
              return $callback($value);
          })->filter(function ($value) {
              return ! is_null($value);
          });
  
          if ($count = $items->count()) {
              return $items->sum() / $count;
          }
      }
  
      /**
       * Get the median of a given key.
       *
       * @param  string|array|null  $key
       * @return mixed
       */
      public function median($key = null)
      {
          $values = (isset($key) ? $this->pluck($key) : $this)
              ->filter(function ($item) {
                  return ! is_null($item);
              })->sort()->values();
  
          $count = $values->count();
  
          if ($count === 0) {
              return;
          }
  
          $middle = (int) ($count / 2);
  
          if ($count % 2) {
              return $values->get($middle);
          }
  
          return (new static([
              $values->get($middle - 1), $values->get($middle),
          ]))->average();
      }
  
      /**
       * Get the mode of a given key.
       *
       * @param  string|array|null  $key
       * @return array|null
       */
      public function mode($key = null)
      {
          if ($this->count() === 0) {
              return;
          }
  
          $collection = isset($key) ? $this->pluck($key) : $this;
  
          $counts = new self;
  
          $collection->each(function ($value) use ($counts) {
              $counts[$value] = isset($counts[$value]) ? $counts[$value] + 1 : 1;
          });
  
          $sorted = $counts->sort();
  
          $highestValue = $sorted->last();
  
          return $sorted->filter(function ($value) use ($highestValue) {
              return $value == $highestValue;
          })->sort()->keys()->all();
      }
  
      /**
       * Collapse the collection of items into a single array.
       *
       * @return static
       */
      public function collapse()
      {
          return new static(Arr::collapse($this->items));
      }
  
      /**
       * Determine if an item exists in the collection.
       *
       * @param  mixed  $key
       * @param  mixed  $operator
       * @param  mixed  $value
       * @return bool
       */
      public function contains($key, $operator = null, $value = null)
      {
          if (func_num_args() === 1) {
              if ($this->useAsCallable($key)) {
                  $placeholder = new stdClass;
  
                  return $this->first($key, $placeholder) !== $placeholder;
              }
  
              return in_array($key, $this->items);
          }
  
          return $this->contains($this->operatorForWhere(...func_get_args()));
      }
  
      /**
       * Cross join with the given lists, returning all possible permutations.
       *
       * @param  mixed  ...$lists
       * @return static
       */
      public function crossJoin(...$lists)
      {
          return new static(Arr::crossJoin(
              $this->items, ...array_map([$this, 'getArrayableItems'], $lists)
          ));
      }
  
      /**
       * Get the items in the collection that are not present in the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function diff($items)
      {
          return new static(array_diff($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Get the items in the collection that are not present in the given items, using the callback.
       *
       * @param  mixed  $items
       * @param  callable  $callback
       * @return static
       */
      public function diffUsing($items, callable $callback)
      {
          return new static(array_udiff($this->items, $this->getArrayableItems($items), $callback));
      }
  
      /**
       * Get the items in the collection whose keys and values are not present in the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function diffAssoc($items)
      {
          return new static(array_diff_assoc($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Get the items in the collection whose keys and values are not present in the given items, using the callback.
       *
       * @param  mixed  $items
       * @param  callable  $callback
       * @return static
       */
      public function diffAssocUsing($items, callable $callback)
      {
          return new static(array_diff_uassoc($this->items, $this->getArrayableItems($items), $callback));
      }
  
      /**
       * Get the items in the collection whose keys are not present in the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function diffKeys($items)
      {
          return new static(array_diff_key($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Get the items in the collection whose keys are not present in the given items, using the callback.
       *
       * @param  mixed  $items
       * @param  callable  $callback
       * @return static
       */
      public function diffKeysUsing($items, callable $callback)
      {
          return new static(array_diff_ukey($this->items, $this->getArrayableItems($items), $callback));
      }
  
      /**
       * Retrieve duplicate items from the collection.
       *
       * @param  callable|null  $callback
       * @param  bool  $strict
       * @return static
       */
      public function duplicates($callback = null, $strict = false)
      {
          $items = $this->map($this->valueRetriever($callback));
  
          $uniqueItems = $items->unique(null, $strict);
  
          $compare = $this->duplicateComparator($strict);
  
          $duplicates = new static;
  
          foreach ($items as $key => $value) {
              if ($uniqueItems->isNotEmpty() && $compare($value, $uniqueItems->first())) {
                  $uniqueItems->shift();
              } else {
                  $duplicates[$key] = $value;
              }
          }
  
          return $duplicates;
      }
  
      /**
       * Retrieve duplicate items from the collection using strict comparison.
       *
       * @param  callable|null  $callback
       * @return static
       */
      public function duplicatesStrict($callback = null)
      {
          return $this->duplicates($callback, true);
      }
  
      /**
       * Get the comparison function to detect duplicates.
       *
       * @param  bool  $strict
       * @return \Closure
       */
      protected function duplicateComparator($strict)
      {
          if ($strict) {
              return function ($a, $b) {
                  return $a === $b;
              };
          }
  
          return function ($a, $b) {
              return $a == $b;
          };
      }
  
      /**
       * Get all items except for those with the specified keys.
       *
       * @param  \Illuminate\Support\Collection|mixed  $keys
       * @return static
       */
      public function except($keys)
      {
          if ($keys instanceof Enumerable) {
              $keys = $keys->all();
          } elseif (! is_array($keys)) {
              $keys = func_get_args();
          }
  
          return new static(Arr::except($this->items, $keys));
      }
  
      /**
       * Run a filter over each of the items.
       *
       * @param  callable|null  $callback
       * @return static
       */
      public function filter(callable $callback = null)
      {
          if ($callback) {
              return new static(Arr::where($this->items, $callback));
          }
  
          return new static(array_filter($this->items));
      }
  
      /**
       * Get the first item from the collection passing the given truth test.
       *
       * @param  callable|null  $callback
       * @param  mixed  $default
       * @return mixed
       */
      public function first(callable $callback = null, $default = null)
      {
          return Arr::first($this->items, $callback, $default);
      }
  
      /**
       * Get a flattened array of the items in the collection.
       *
       * @param  int  $depth
       * @return static
       */
      public function flatten($depth = INF)
      {
          return new static(Arr::flatten($this->items, $depth));
      }
  
      /**
       * Flip the items in the collection.
       *
       * @return static
       */
      public function flip()
      {
          return new static(array_flip($this->items));
      }
  
      /**
       * Remove an item from the collection by key.
       *
       * @param  string|array  $keys
       * @return $this
       */
      public function forget($keys)
      {
          foreach ((array) $keys as $key) {
              $this->offsetUnset($key);
          }
  
          return $this;
      }
  
      /**
       * Get an item from the collection by key.
       *
       * @param  mixed  $key
       * @param  mixed  $default
       * @return mixed
       */
      public function get($key, $default = null)
      {
          if ($this->offsetExists($key)) {
              return $this->items[$key];
          }
  
          return value($default);
      }
  
      /**
       * Group an associative array by a field or using a callback.
       *
       * @param  array|callable|string  $groupBy
       * @param  bool  $preserveKeys
       * @return static
       */
      public function groupBy($groupBy, $preserveKeys = false)
      {
          if (! $this->useAsCallable($groupBy) && is_array($groupBy)) {
              $nextGroups = $groupBy;
  
              $groupBy = array_shift($nextGroups);
          }
  
          $groupBy = $this->valueRetriever($groupBy);
  
          $results = [];
  
          foreach ($this->items as $key => $value) {
              $groupKeys = $groupBy($value, $key);
  
              if (! is_array($groupKeys)) {
                  $groupKeys = [$groupKeys];
              }
  
              foreach ($groupKeys as $groupKey) {
                  $groupKey = is_bool($groupKey) ? (int) $groupKey : $groupKey;
  
                  if (! array_key_exists($groupKey, $results)) {
                      $results[$groupKey] = new static;
                  }
  
                  $results[$groupKey]->offsetSet($preserveKeys ? $key : null, $value);
              }
          }
  
          $result = new static($results);
  
          if (! empty($nextGroups)) {
              return $result->map->groupBy($nextGroups, $preserveKeys);
          }
  
          return $result;
      }
  
      /**
       * Key an associative array by a field or using a callback.
       *
       * @param  callable|string  $keyBy
       * @return static
       */
      public function keyBy($keyBy)
      {
          $keyBy = $this->valueRetriever($keyBy);
  
          $results = [];
  
          foreach ($this->items as $key => $item) {
              $resolvedKey = $keyBy($item, $key);
  
              if (is_object($resolvedKey)) {
                  $resolvedKey = (string) $resolvedKey;
              }
  
              $results[$resolvedKey] = $item;
          }
  
          return new static($results);
      }
  
      /**
       * Determine if an item exists in the collection by key.
       *
       * @param  mixed  $key
       * @return bool
       */
      public function has($key)
      {
          $keys = is_array($key) ? $key : func_get_args();
  
          foreach ($keys as $value) {
              if (! $this->offsetExists($value)) {
                  return false;
              }
          }
  
          return true;
      }
  
      /**
       * Concatenate values of a given key as a string.
       *
       * @param  string  $value
       * @param  string|null  $glue
       * @return string
       */
      public function implode($value, $glue = null)
      {
          $first = $this->first();
  
          if (is_array($first) || is_object($first)) {
              return implode($glue, $this->pluck($value)->all());
          }
  
          return implode($value, $this->items);
      }
  
      /**
       * Intersect the collection with the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function intersect($items)
      {
          return new static(array_intersect($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Intersect the collection with the given items by key.
       *
       * @param  mixed  $items
       * @return static
       */
      public function intersectByKeys($items)
      {
          return new static(array_intersect_key(
              $this->items, $this->getArrayableItems($items)
          ));
      }
  
      /**
       * Determine if the collection is empty or not.
       *
       * @return bool
       */
      public function isEmpty()
      {
          return empty($this->items);
      }
  
      /**
       * Join all items from the collection using a string. The final items can use a separate glue string.
       *
       * @param  string  $glue
       * @param  string  $finalGlue
       * @return string
       */
      public function join($glue, $finalGlue = '')
      {
          if ($finalGlue === '') {
              return $this->implode($glue);
          }
  
          $count = $this->count();
  
          if ($count === 0) {
              return '';
          }
  
          if ($count === 1) {
              return $this->last();
          }
  
          $collection = new static($this->items);
  
          $finalItem = $collection->pop();
  
          return $collection->implode($glue).$finalGlue.$finalItem;
      }
  
      /**
       * Get the keys of the collection items.
       *
       * @return static
       */
      public function keys()
      {
          return new static(array_keys($this->items));
      }
  
      /**
       * Get the last item from the collection.
       *
       * @param  callable|null  $callback
       * @param  mixed  $default
       * @return mixed
       */
      public function last(callable $callback = null, $default = null)
      {
          return Arr::last($this->items, $callback, $default);
      }
  
      /**
       * Get the values of a given key.
       *
       * @param  string|array  $value
       * @param  string|null  $key
       * @return static
       */
      public function pluck($value, $key = null)
      {
          return new static(Arr::pluck($this->items, $value, $key));
      }
  
      /**
       * Run a map over each of the items.
       *
       * @param  callable  $callback
       * @return static
       */
      public function map(callable $callback)
      {
          $keys = array_keys($this->items);
  
          $items = array_map($callback, $this->items, $keys);
  
          return new static(array_combine($keys, $items));
      }
  
      /**
       * Run a dictionary map over the items.
       *
       * The callback should return an associative array with a single key/value pair.
       *
       * @param  callable  $callback
       * @return static
       */
      public function mapToDictionary(callable $callback)
      {
          $dictionary = [];
  
          foreach ($this->items as $key => $item) {
              $pair = $callback($item, $key);
  
              $key = key($pair);
  
              $value = reset($pair);
  
              if (! isset($dictionary[$key])) {
                  $dictionary[$key] = [];
              }
  
              $dictionary[$key][] = $value;
          }
  
          return new static($dictionary);
      }
  
      /**
       * Run an associative map over each of the items.
       *
       * The callback should return an associative array with a single key/value pair.
       *
       * @param  callable  $callback
       * @return static
       */
      public function mapWithKeys(callable $callback)
      {
          $result = [];
  
          foreach ($this->items as $key => $value) {
              $assoc = $callback($value, $key);
  
              foreach ($assoc as $mapKey => $mapValue) {
                  $result[$mapKey] = $mapValue;
              }
          }
  
          return new static($result);
      }
  
      /**
       * Merge the collection with the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function merge($items)
      {
          return new static(array_merge($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Recursively merge the collection with the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function mergeRecursive($items)
      {
          return new static(array_merge_recursive($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Create a collection by using this collection for keys and another for its values.
       *
       * @param  mixed  $values
       * @return static
       */
      public function combine($values)
      {
          return new static(array_combine($this->all(), $this->getArrayableItems($values)));
      }
  
      /**
       * Union the collection with the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function union($items)
      {
          return new static($this->items + $this->getArrayableItems($items));
      }
  
      /**
       * Create a new collection consisting of every n-th element.
       *
       * @param  int  $step
       * @param  int  $offset
       * @return static
       */
      public function nth($step, $offset = 0)
      {
          $new = [];
  
          $position = 0;
  
          foreach ($this->items as $item) {
              if ($position % $step === $offset) {
                  $new[] = $item;
              }
  
              $position++;
          }
  
          return new static($new);
      }
  
      /**
       * Get the items with the specified keys.
       *
       * @param  mixed  $keys
       * @return static
       */
      public function only($keys)
      {
          if (is_null($keys)) {
              return new static($this->items);
          }
  
          if ($keys instanceof Enumerable) {
              $keys = $keys->all();
          }
  
          $keys = is_array($keys) ? $keys : func_get_args();
  
          return new static(Arr::only($this->items, $keys));
      }
  
      /**
       * Get and remove the last item from the collection.
       *
       * @return mixed
       */
      public function pop()
      {
          return array_pop($this->items);
      }
  
      /**
       * Push an item onto the beginning of the collection.
       *
       * @param  mixed  $value
       * @param  mixed  $key
       * @return $this
       */
      public function prepend($value, $key = null)
      {
          $this->items = Arr::prepend($this->items, $value, $key);
  
          return $this;
      }
  
      /**
       * Push one or more items onto the end of the collection.
       *
       * @param  mixed  $values
       * @return $this
       */
      public function push(...$values)
      {
          foreach ($values as $value) {
              $this->items[] = $value;
          }
  
          return $this;
      }
  
      /**
       * Push all of the given items onto the collection.
       *
       * @param  iterable  $source
       * @return static
       */
      public function concat($source)
      {
          $result = new static($this);
  
          foreach ($source as $item) {
              $result->push($item);
          }
  
          return $result;
      }
  
      /**
       * Get and remove an item from the collection.
       *
       * @param  mixed  $key
       * @param  mixed  $default
       * @return mixed
       */
      public function pull($key, $default = null)
      {
          return Arr::pull($this->items, $key, $default);
      }
  
      /**
       * Put an item in the collection by key.
       *
       * @param  mixed  $key
       * @param  mixed  $value
       * @return $this
       */
      public function put($key, $value)
      {
          $this->offsetSet($key, $value);
  
          return $this;
      }
  
      /**
       * Get one or a specified number of items randomly from the collection.
       *
       * @param  int|null  $number
       * @return static|mixed
       *
       * @throws \InvalidArgumentException
       */
      public function random($number = null)
      {
          if (is_null($number)) {
              return Arr::random($this->items);
          }
  
          return new static(Arr::random($this->items, $number));
      }
  
      /**
       * Reduce the collection to a single value.
       *
       * @param  callable  $callback
       * @param  mixed  $initial
       * @return mixed
       */
      public function reduce(callable $callback, $initial = null)
      {
          return array_reduce($this->items, $callback, $initial);
      }
  
      /**
       * Replace the collection items with the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function replace($items)
      {
          return new static(array_replace($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Recursively replace the collection items with the given items.
       *
       * @param  mixed  $items
       * @return static
       */
      public function replaceRecursive($items)
      {
          return new static(array_replace_recursive($this->items, $this->getArrayableItems($items)));
      }
  
      /**
       * Reverse items order.
       *
       * @return static
       */
      public function reverse()
      {
          return new static(array_reverse($this->items, true));
      }
  
      /**
       * Search the collection for a given value and return the corresponding key if successful.
       *
       * @param  mixed  $value
       * @param  bool  $strict
       * @return mixed
       */
      public function search($value, $strict = false)
      {
          if (! $this->useAsCallable($value)) {
              return array_search($value, $this->items, $strict);
          }
  
          foreach ($this->items as $key => $item) {
              if ($value($item, $key)) {
                  return $key;
              }
          }
  
          return false;
      }
  
      /**
       * Get and remove the first item from the collection.
       *
       * @return mixed
       */
      public function shift()
      {
          return array_shift($this->items);
      }
  
      /**
       * Shuffle the items in the collection.
       *
       * @param  int|null  $seed
       * @return static
       */
      public function shuffle($seed = null)
      {
          return new static(Arr::shuffle($this->items, $seed));
      }
  
      /**
       * Skip the first {$count} items.
       *
       * @param  int  $count
       * @return static
       */
      public function skip($count)
      {
          return $this->slice($count);
      }
  
      /**
       * Skip items in the collection until the given condition is met.
       *
       * @param  mixed  $value
       * @return static
       */
      public function skipUntil($value)
      {
          return new static($this->lazy()->skipUntil($value)->all());
      }
  
      /**
       * Skip items in the collection while the given condition is met.
       *
       * @param  mixed  $value
       * @return static
       */
      public function skipWhile($value)
      {
          return new static($this->lazy()->skipWhile($value)->all());
      }
  
      /**
       * Slice the underlying collection array.
       *
       * @param  int  $offset
       * @param  int|null  $length
       * @return static
       */
      public function slice($offset, $length = null)
      {
          return new static(array_slice($this->items, $offset, $length, true));
      }
  
      /**
       * Split a collection into a certain number of groups.
       *
       * @param  int  $numberOfGroups
       * @return static
       */
      public function split($numberOfGroups)
      {
          if ($this->isEmpty()) {
              return new static;
          }
  
          $groups = new static;
  
          $groupSize = floor($this->count() / $numberOfGroups);
  
          $remain = $this->count() % $numberOfGroups;
  
          $start = 0;
  
          for ($i = 0; $i < $numberOfGroups; $i++) {
              $size = $groupSize;
  
              if ($i < $remain) {
                  $size++;
              }
  
              if ($size) {
                  $groups->push(new static(array_slice($this->items, $start, $size)));
  
                  $start += $size;
              }
          }
  
          return $groups;
      }
  
      /**
       * Chunk the collection into chunks of the given size.
       *
       * @param  int  $size
       * @return static
       */
      public function chunk($size)
      {
          if ($size <= 0) {
              return new static;
          }
  
          $chunks = [];
  
          foreach (array_chunk($this->items, $size, true) as $chunk) {
              $chunks[] = new static($chunk);
          }
  
          return new static($chunks);
      }
  
      /**
       * Sort through each item with a callback.
       *
       * @param  callable|int|null  $callback
       * @return static
       */
      public function sort($callback = null)
      {
          $items = $this->items;
  
          $callback && is_callable($callback)
              ? uasort($items, $callback)
              : asort($items, $callback);
  
          return new static($items);
      }
  
      /**
       * Sort items in descending order.
       *
       * @param  int  $options
       * @return static
       */
      public function sortDesc($options = SORT_REGULAR)
      {
          $items = $this->items;
  
          arsort($items, $options);
  
          return new static($items);
      }
  
      /**
       * Sort the collection using the given callback.
       *
       * @param  callable|string  $callback
       * @param  int  $options
       * @param  bool  $descending
       * @return static
       */
      public function sortBy($callback, $options = SORT_REGULAR, $descending = false)
      {
          $results = [];
  
          $callback = $this->valueRetriever($callback);
  
          // First we will loop through the items and get the comparator from a callback
          // function which we were given. Then, we will sort the returned values and
          // and grab the corresponding values for the sorted keys from this array.
          foreach ($this->items as $key => $value) {
              $results[$key] = $callback($value, $key);
          }
  
          $descending ? arsort($results, $options)
              : asort($results, $options);
  
          // Once we have sorted all of the keys in the array, we will loop through them
          // and grab the corresponding model so we can set the underlying items list
          // to the sorted version. Then we'll just return the collection instance.
          foreach (array_keys($results) as $key) {
              $results[$key] = $this->items[$key];
          }
  
          return new static($results);
      }
  
      /**
       * Sort the collection in descending order using the given callback.
       *
       * @param  callable|string  $callback
       * @param  int  $options
       * @return static
       */
      public function sortByDesc($callback, $options = SORT_REGULAR)
      {
          return $this->sortBy($callback, $options, true);
      }
  
      /**
       * Sort the collection keys.
       *
       * @param  int  $options
       * @param  bool  $descending
       * @return static
       */
      public function sortKeys($options = SORT_REGULAR, $descending = false)
      {
          $items = $this->items;
  
          $descending ? krsort($items, $options) : ksort($items, $options);
  
          return new static($items);
      }
  
      /**
       * Sort the collection keys in descending order.
       *
       * @param  int  $options
       * @return static
       */
      public function sortKeysDesc($options = SORT_REGULAR)
      {
          return $this->sortKeys($options, true);
      }
  
      /**
       * Splice a portion of the underlying collection array.
       *
       * @param  int  $offset
       * @param  int|null  $length
       * @param  mixed  $replacement
       * @return static
       */
      public function splice($offset, $length = null, $replacement = [])
      {
          if (func_num_args() === 1) {
              return new static(array_splice($this->items, $offset));
          }
  
          return new static(array_splice($this->items, $offset, $length, $replacement));
      }
  
      /**
       * Take the first or last {$limit} items.
       *
       * @param  int  $limit
       * @return static
       */
      public function take($limit)
      {
          if ($limit < 0) {
              return $this->slice($limit, abs($limit));
          }
  
          return $this->slice(0, $limit);
      }
  
      /**
       * Take items in the collection until the given condition is met.
       *
       * @param  mixed  $value
       * @return static
       */
      public function takeUntil($value)
      {
          return new static($this->lazy()->takeUntil($value)->all());
      }
  
      /**
       * Take items in the collection while the given condition is met.
       *
       * @param  mixed  $value
       * @return static
       */
      public function takeWhile($value)
      {
          return new static($this->lazy()->takeWhile($value)->all());
      }
  
      /**
       * Transform each item in the collection using a callback.
       *
       * @param  callable  $callback
       * @return $this
       */
      public function transform(callable $callback)
      {
          $this->items = $this->map($callback)->all();
  
          return $this;
      }
  
      /**
       * Reset the keys on the underlying array.
       *
       * @return static
       */
      public function values()
      {
          return new static(array_values($this->items));
      }
  
      /**
       * Zip the collection together with one or more arrays.
       *
       * e.g. new Collection([1, 2, 3])->zip([4, 5, 6]);
       *      => [[1, 4], [2, 5], [3, 6]]
       *
       * @param  mixed  ...$items
       * @return static
       */
      public function zip($items)
      {
          $arrayableItems = array_map(function ($items) {
              return $this->getArrayableItems($items);
          }, func_get_args());
  
          $params = array_merge([function () {
              return new static(func_get_args());
          }, $this->items], $arrayableItems);
  
          return new static(array_map(...$params));
      }
  
      /**
       * Pad collection to the specified length with a value.
       *
       * @param  int  $size
       * @param  mixed  $value
       * @return static
       */
      public function pad($size, $value)
      {
          return new static(array_pad($this->items, $size, $value));
      }
  
      /**
       * Get an iterator for the items.
       *
       * @return \ArrayIterator
       */
      public function getIterator()
      {
          return new ArrayIterator($this->items);
      }
  
      /**
       * Count the number of items in the collection.
       *
       * @return int
       */
      public function count()
      {
          return count($this->items);
      }
  
      /**
       * Count the number of items in the collection by a field or using a callback.
       *
       * @param  callable|string  $countBy
       * @return static
       */
      public function countBy($countBy = null)
      {
          return new static($this->lazy()->countBy($countBy)->all());
      }
  
      /**
       * Add an item to the collection.
       *
       * @param  mixed  $item
       * @return $this
       */
      public function add($item)
      {
          $this->items[] = $item;
  
          return $this;
      }
  
      /**
       * Get a base Support collection instance from this collection.
       *
       * @return \Illuminate\Support\Collection
       */
      public function toBase()
      {
          return new self($this);
      }
  
      /**
       * Determine if an item exists at an offset.
       *
       * @param  mixed  $key
       * @return bool
       */
      public function offsetExists($key)
      {
          return array_key_exists($key, $this->items);
      }
  
      /**
       * Get an item at a given offset.
       *
       * @param  mixed  $key
       * @return mixed
       */
      public function offsetGet($key)
      {
          return $this->items[$key];
      }
  
      /**
       * Set the item at a given offset.
       *
       * @param  mixed  $key
       * @param  mixed  $value
       * @return void
       */
      public function offsetSet($key, $value)
      {
          if (is_null($key)) {
              $this->items[] = $value;
          } else {
              $this->items[$key] = $value;
          }
      }
  
      /**
       * Unset the item at a given offset.
       *
       * @param  string  $key
       * @return void
       */
      public function offsetUnset($key)
      {
          unset($this->items[$key]);
      }
  }