setUserProperties method
Adds properties that are tracked on the user level.
Note: Property keys must be String objects and values must be serializable.
Implementation
Future<void> setUserProperties(Map<String, dynamic> userProperties) async {
Map<String, dynamic> properties = _baseProperties();
properties['userProperties'] = userProperties;
return await _channel.invokeMethod(
'setUserProperties', jsonEncode(properties));
}