wp_register_layout_support( WP_Block_Type $block_type )

455function wp_register_layout_support( $block_type ) {456	$support_layout = block_has_support( $block_type, 'layout', false ) || block_has_support( $block_type, '__experimentalLayout', false );457	if ( $support_layout ) {458		if ( ! $block_type->attributes ) {459			$block_type->attributes = array();460		}461 462		if ( ! array_key_exists( 'layout', $block_type->attributes ) ) {463			$block_type->attributes['layout'] = array(464				'type' => 'object',465			);466		}467	}468}