*
	 * @return array Item schema data.
	 */
	public function get_item_schema() {
		if ( $this->schema ) {
			return $this->add_additional_fields_schema( $this->schema );
		}

		$schema = $this->parent_controller->get_item_schema();

		$schema['properties']['parent'] = array(
			'description' => __( 'The ID for the parent of the revision.' ),
			'type'        => 'integer',
			'context'     => array( 'view', 'edit', 'embed' ),
		);

		$this->schema = $schema;

		return $this->add_additional_fields_schema( $this->schema );
	}
}