registerManager method
Implementation
void registerManager(String className, AbsExModelManager manager, {String postfix = 'onlyOne'}) {
Map<String, AbsExModelManager>? map = _managerMap[className];
//print('registerManager $className, $postfix');
if (map == null) {
map = {postfix: manager};
_managerMap[className] = map;
} else {
map[postfix] = manager;
}
}