public function validate_attendee_meta( $ticket_id, $data ) {
		if ( ! tribe_tickets_has_meta_fields( $ticket_id ) ) {
			return new WP_Error( 'invalid-meta-fields', __( 'This attendee has no meta fields associated with it.', 'event-tickets-plus' ), [ 'status' => 400 ] );
		}

		$meta_fields   = (array) get_post_meta( $ticket_id, Tribe__Tickets_Plus__Meta::META_KEY , true );
		$attendee_meta = $data['attendee_meta'];

		foreach ( $meta_fields as $field ) {
			if ( 'on' === $field['required'] && ! isset( $attendee_meta[ $field[ 'slug' ] ] ) ) {
				return new WP_Error( 'missing-required-meta-fields', __( 'Some required attendee data is missing.', 'event-tickets-plus' ), [ 'status' => 400, 'attendee_meta' => $meta_fields ] );
			}
		}

		return $data;
	}