code: protected function _getData($key)
      {
          $store = $this->_getDataStore();
  
          try {
              $result = $this->_containerGet($store, $key);
          } catch (OutOfRangeException $e) {
              throw $this->_createInvalidArgumentException($this->__('Invalid key'), null, $e, $key);
          }
  
          return $result;
      }
docs: Retrieve data, all or by key.
  
  @since [*next-version*]
  
  @param string|int|float|bool|Stringable $key The key, for which to get the data.
  Unless an integer is given, this will be normalized to string.
  
  @throws InvalidArgumentException    If key is invalid.
  @throws ContainerExceptionInterface If an error occurred while reading from the container.
  @throws NotFoundExceptionInterface  If the key was not found in the container.
  
  @return mixed The value for the specified key.