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

@return  bool
Test if current y column is valid