code: public function get($id)
      {
          if ($this->has($id) === true) {
              $entry = isset($this->instances[$id]) ? $this->instances[$id] : $this->resolve($id);
  
              if (is_object($entry) === false) {
                  $message = (string) 'Alias (%s) is not an object';
  
                  $message = sprintf($message, $id);
  
                  throw new Exception\ContainerException($message);
              }
  
              return $entry;
          }
  
          $message = 'Alias (%s) is not being managed by the container';
  
          throw new Exception\NotFoundException(sprintf($message, $id));
      }
docs: Finds an entry of the container by its identifier and returns it.
  
  @throws \Psr\Container\NotFoundExceptionInterface
  @throws \Psr\Container\ContainerExceptionInterface
  
  @param  string $id
  @return mixed