implementor      1961 ext/date/php_date.c static int implement_date_interface_handler(zend_class_entry *interface, zend_class_entry *implementor) /* {{{ */
implementor      1963 ext/date/php_date.c 	if (implementor->type == ZEND_USER_CLASS &&
implementor      1964 ext/date/php_date.c 		!instanceof_function(implementor, date_ce_date) &&
implementor      1965 ext/date/php_date.c 		!instanceof_function(implementor, date_ce_immutable)