protected function get_query_url() {
		if ( property_exists( $this, 'query_url' ) ) {
			return $this->query_url;
		}

		$url = admin_url( 'admin-ajax.php' );

		/**
		 * Filters the post arguments used during an async request.
		 *
		 * @param string $url
		 */
		return apply_filters( $this->identifier . '_query_url', $url );
	}