protected function update_additional_object_fields( $membership, $request, $schema, $prepared_item, $creating = true ) {
		$error = new WP_Error();

		// Auto enroll.
		if ( ! empty( $schema['properties']['auto_enroll'] ) && isset( $request['auto_enroll'] ) ) {
			$membership->add_auto_enroll_courses( $request['auto_enroll'], true );
		}

		// Catalog visibility.
		if ( ! empty( $schema['properties']['catalog_visibility'] ) && isset( $request['catalog_visibility'] ) ) {
			$membership->get_product()->set_catalog_visibility( $request['catalog_visibility'] );
		}

		// Instructors.
		if ( ! empty( $schema['properties']['instructors'] ) ) {

			$instructors = array();

			if ( isset( $request['instructors'] ) ) {
				foreach ( $request['instructors'] as $instructor_id ) {
					$user_data = get_userdata( $instructor_id );
					if ( ! empty( $user_data ) ) {
						$instructors[] = array(
							'id'   => $instructor_id,
							'name' => $user_data->display_name,
						);
					}
				}
			}

			// When creating, always make sure the instructors are set.
			// Note: `$membership->set_instructor( $instructors )` when `$instructors` is empty
			// will set the membership's author as membership's instructor.
			if ( $membership || ( ! $creating && isset( $request['instructors'] ) ) ) {
				$membership->set_instructors( $instructors );
			}
		}

		$to_set = array();

		/**
		 * The following properties have a default value that contains a placeholder, e.g. `{{membership_id}}`,
		 * that can be "expanded" only after the membership has been created.
		 */
		// Restriction message.
		if ( ! empty( $schema['properties']['restriction_message'] ) ) {
			if ( isset( $request['restriction_message'] ) ) {
				if ( is_string( $request['restriction_message'] ) ) {
					$to_set['restriction_notice'] = $request['restriction_message'];
				} elseif ( isset( $request['restriction_message']['raw'] ) ) {
					$to_set['restriction_notice'] = $request['restriction_message']['raw'];
				}
			} elseif ( $creating ) {
				$to_set['restriction_notice'] = $schema['properties']['restriction_message']['properties']['raw']['default'];
			}
		}

		// Needed until the following will be implemented: https://github.com/gocodebox/lifterlms/issues/908.
		// On creation, since the restriction message has a non empty default, the restriction_add_notice,
		// will be set to 'yes'.
		$to_set['restriction_add_notice'] = empty( $to_set['restriction_notice'] ) ? 'no' : 'yes';

		// Are we creating a membership? TODO what about updating when message is empty?
		// If so, replace the placeholder with the actual membership id.
		if ( $creating ) {
			$_to_expand_props = array(
				'restriction_notice',
			);
			$membership_id    = $membership->get( 'id' );
			foreach ( $_to_expand_props as $prop ) {
				if ( ! empty( $to_set[ $prop ] ) ) {
					$to_set[ $prop ] = str_replace( '{{membership_id}}', $membership_id, $to_set[ $prop ] );
				}
			}
		}

		// Set bulk.
		if ( ! empty( $to_set ) ) {
			$update = $membership->set_bulk( $to_set, true, true );
			if ( is_wp_error( $update ) ) {
				$error = $update;
			}
		}

		if ( $error->errors ) {
			return $error;
		}

		return ! empty( $to_set );
	}