public function add_query_vars( $vars = array() ) {
		if ( ! empty( $this->rewrite_endpoint ) ) {
			$keys = array_keys( $this->rewrite_endpoint );
			return array_merge( $vars, $keys );
		}
		return $vars;
	}
public function add_query_vars( $vars = array() ) {
		if ( ! empty( $this->rewrite_endpoint ) ) {
			$keys = array_keys( $this->rewrite_endpoint );
			return array_merge( $vars, $keys );
		}
		return $vars;
	}
public function add_query_vars ( $ vars = array ( ) ) { if ( ! empty ( $ this -> rewrite_endpoint ) ) { $ keys = array_keys ( $ this -> rewrite_endpoint ) ; return array_merge ( $ vars , $ keys ) ; } return $ vars ; }
Adds Custom Query Vars TO WordPress.

@param array $vars

@return array
Adds Custom Query Vars TO WordPress .