has method
Implementation
bool has(dynamic keys) {
if (keys is String) {
String? val = _all[keys];
if (val == null) {
return false;
}
return val.toString().isNotEmpty ? true : false;
}
if (keys is List<String>) {
bool hasKey = true;
for (String key in keys) {
if (_all[key] == null) {
hasKey = false;
}
}
return hasKey;
}
return (_all[keys] != null && _all[keys].toString().isNotEmpty);
}