original_string: public function set($key, $val)
      {
          $this->_data = Hash::merge([$key => $val], $this->_data);
          return $this;
      }
code: public function set($key, $val)
      {
          $this->_data = Hash::merge([$key => $val], $this->_data);
          return $this;
      }
code_tokens: public function set ( $ key , $ val ) { $ this -> _data = Hash :: merge ( [ $ key => $ val ] , $ this -> _data ) ; return $ this ; }
docstring: Add new value in list.
  
  @param   string|int $key
  @param   string|int $val
  @return  $this
docstring_tokens: Add new value in list .