original_string: public function append($string, $length = null)
      {
          $this->end();
          return $this->write($string, $length);
      }
code: public function append($string, $length = null)
      {
          $this->end();
          return $this->write($string, $length);
      }
code_tokens: public function append ( $ string , $ length = null ) { $ this -> end ( ) ; return $ this -> write ( $ string , $ length ) ; }
docstring: Append data to the stream.
  
  @param  string  $string The string that is to be written.
  @param  integer $length If the length argument is given, writing will stop after length bytes have
  been written or the end of string if reached, whichever comes first.
  @return integer         Number of bytes written
docstring_tokens: Append data to the stream .