<?php
  
  declare(strict_types=1);
  
  namespace Psr\Container;
  
  /**
   * Describes the interface of a container that exposes methods to read its entries.
   */
  interface ContainerInterface
  {
      /**
       * Finds an entry of the container by its identifier and returns it.
       *
       * @param string $id Identifier of the entry to look for.
       *
       * @throws NotFoundExceptionInterface  No entry was found for **this** identifier.
       * @throws ContainerExceptionInterface Error while retrieving the entry.
       *
       * @return mixed Entry.
       */
      public function get(string $id);
  
      /**
       * Returns true if the container can return an entry for the given identifier.
       * Returns false otherwise.
       *
       * `has($id)` returning true does not mean that `get($id)` will not throw an exception.
       * It does however mean that `get($id)` will not throw a `NotFoundExceptionInterface`.
       *
       * @param string $id Identifier of the entry to look for.
       *
       * @return bool
       */
      public function has(string $id);
  }