user method
设置用户及其权限
Implementation
BmobACL user(BmobUserTable user, {bool read = false, bool write = false}) {
if (user.objectId.isEmpty) throw Exception('user objectId is empty');
if (read || write) {
_acl[user.objectId] = _createCAL(read, write);
} else {
_acl.remove(user.objectId);
}
return this;
}