public function validX()
    {
        return (bool) (!is_null($this->keyX()) && isset($this->data[$this->keyX(true)]));
    }
public function validX()
    {
        return (bool) (!is_null($this->keyX()) && isset($this->data[$this->keyX(true)]));
    }
public function validX ( ) { return ( bool ) ( ! is_null ( $ this -> keyX ( ) ) && isset ( $ this -> data [ $ this -> keyX ( true ) ] ) ) ; }
Test if current `x` line is valid

@return  bool
Test if current x line is valid