WP_REST_Sidebars_Controller::do_permissions_check()

	protected function do_permissions_check() {
		// Verify if the current user has edit_theme_options capability.
		// This capability is required to access the widgets screen.
		if ( ! current_user_can( 'edit_theme_options' ) ) {
			return new WP_Error(
				'rest_cannot_manage_widgets',
				__( 'Sorry, you are not allowed to manage widgets on this site.' ),
				array( 'status' => rest_authorization_required_code() )
			);
		}

		return true;
	}