protected function get_object_id( $object ) {
		if ( is_object( $object ) && ! empty( $object->id ) ) {
			return $object->id;
		} elseif ( is_array( $object ) && ! empty( $object['id'] ) ) {
			return $object['id'];
		} elseif ( method_exists( $object, 'get_id' ) ) {
			return $object->get_id();
		} elseif ( method_exists( $object, 'get' ) ) {
			return $object->get( 'id' );
		}

		// @todo: add version to message.

		// Translators: %s = method name.
		_doing_it_wrong( 'LLMS_REST_Controller::get_object_id', sprintf( __( "Method '%s' must be overridden.", 'lifterlms' ), __METHOD__ ), '1.0.0-beta.1' );

		// For example.
		return 0;

	}