public function query_vars( array $vars ){
        if( !empty($this->query_var) ){
            foreach( $this->query_var as $var ){
                if( false === array_search($var, $vars) ){
                    $vars[] = $var;
                }
            }
        }
        return $vars;
    }
public function query_vars( array $vars ){
        if( !empty($this->query_var) ){
            foreach( $this->query_var as $var ){
                if( false === array_search($var, $vars) ){
                    $vars[] = $var;
                }
            }
        }
        return $vars;
    }
public function query_vars ( array $ vars ) { if ( ! empty ( $ this -> query_var ) ) { foreach ( $ this -> query_var as $ var ) { if ( false === array_search ( $ var , $ vars ) ) { $ vars [ ] = $ var ; } } } return $ vars ; }
Add query var filter

@param array $vars
@return array
Add query var filter