public function valid()
    {
        return isset($this->base['value'][$this->position]) && is_array($this->base['value'][$this->position]);
    }
public function valid()
    {
        return isset($this->base['value'][$this->position]) && is_array($this->base['value'][$this->position]);
    }
public function valid ( ) { return isset ( $ this -> base [ 'value' ] [ $ this -> position ] ) && is_array ( $ this -> base [ 'value' ] [ $ this -> position ] ) ; }
Check if current position is valid.

@return boolean
Check if current position is valid .