WordPress at a glance
function is not described

WP_REST_Revisions_Controller::get_parent() protected WP 4.7.2

Get the parent post, if the ID is valid.

It's a method of the class: WP_REST_Revisions_Controller{}

No Hooks.

Return

WP_Post/WP_Error. Post object if ID is valid, WP_Error otherwise.

Usage

// protected - for code of main (parent) or child class
$result = $this->get_parent( $parent );
$parent(int) (required)
Supplied ID.

Changelog

Since 4.7.2 Introduced.

Code of WP_REST_Revisions_Controller::get_parent() WP 5.5.1

<?php
protected function get_parent( $parent ) {
	$error = new WP_Error(
		'rest_post_invalid_parent',
		__( 'Invalid post parent ID.' ),
		array( 'status' => 404 )
	);
	if ( (int) $parent <= 0 ) {
		return $error;
	}

	$parent = get_post( (int) $parent );
	if ( empty( $parent ) || empty( $parent->ID ) || $this->parent_post_type !== $parent->post_type ) {
		return $error;
	}

	return $parent;
}