WP_Metadata_Lazyloader::queue_objects( string $object_type, array $object_ids )

	public function queue_objects( $object_type, $object_ids ) {
		if ( ! isset( $this->settings[ $object_type ] ) ) {
			return new WP_Error( 'invalid_object_type', __( 'Invalid object type' ) );
		}

		$type_settings = $this->settings[ $object_type ];

		if ( ! isset( $this->pending_objects[ $object_type ] ) ) {
			$this->pending_objects[ $object_type ] = array();
		}

		foreach ( $object_ids as $object_id ) {
			// Keyed by ID for faster lookup.
			if ( ! isset( $this->pending_objects[ $object_type ][ $object_id ] ) ) {
				$this->pending_objects[ $object_type ][ $object_id ] = 1;
			}
		}

		add_filter( $type_settings['filter'], $type_settings['callback'] );

		/**
		 * Fires after objects are added to the metadata lazy-load queue.
		 *
		 * @since WP-4.5.0
		 *
		 * @param array                  $object_ids  Object IDs.
		 * @param string                 $object_type Type of object being queued.
		 * @param WP_Metadata_Lazyloader $lazyloader  The lazy-loader object.
		 */
		do_action( 'metadata_lazyloader_queued_objects', $object_ids, $object_type, $this );
	}