public function set($key, $val)
    {
        $this->_data = Hash::merge([$key => $val], $this->_data);
        return $this;
    }
public function set($key, $val)
    {
        $this->_data = Hash::merge([$key => $val], $this->_data);
        return $this;
    }
public function set ( $ key , $ val ) { $ this -> _data = Hash :: merge ( [ $ key => $ val ] , $ this -> _data ) ; return $ this ; }
Add new value in list.

@param   string|int $key
@param   string|int $val
@return  $this
Add new value in list .