protected static function append_user_fullnames( $activities ) {

		if ( bp_is_active( 'xprofile' ) && ! empty( $activities ) ) {
			$activity_user_ids = wp_list_pluck( $activities, 'user_id' );

			if ( ! empty( $activity_user_ids ) ) {
				$fullnames = bp_core_get_user_displaynames( $activity_user_ids );
				if ( ! empty( $fullnames ) ) {
					foreach ( (array) $activities as $i => $activity ) {
						if ( ! empty( $fullnames[ $activity->user_id ] ) ) {
							$activities[ $i ]->user_fullname = $fullnames[ $activity->user_id ];
						}
					}
				}
			}
		}

		return $activities;
	}