original_string: protected function _setCallbackFilter($filter)
      {
          if (!is_callable($filter, true) && !is_null($filter)) {
              throw new InvalidArgumentException('Filter must be a callable');
          }
  
          $this->callbackFilter = $filter;
  
          return $this;
      }
code: protected function _setCallbackFilter($filter)
      {
          if (!is_callable($filter, true) && !is_null($filter)) {
              throw new InvalidArgumentException('Filter must be a callable');
          }
  
          $this->callbackFilter = $filter;
  
          return $this;
      }
code_tokens: protected function _setCallbackFilter ( $ filter ) { if ( ! is_callable ( $ filter , true ) && ! is_null ( $ filter ) ) { throw new InvalidArgumentException ( 'Filter must be a callable' ) ; } $ this -> callbackFilter = $ filter ; return $ this ; }
docstring: Assigns the filter that is optionally used to filter files.
  
  @since [*next-version*]
  
  @param callable|null $filter The callback.
  
  @throws InvalidArgumentException If the filter is not a callable.
  
  @return $this
docstring_tokens: Assigns the filter that is optionally used to filter files .