registerSuperProperties method Null safety
Register properties that will be sent with every subsequent call to track().
SuperProperties are a collection of properties that will be sent with every event to Mixpanel, and persist beyond the lifetime of your application.
Setting a superProperty with registerSuperProperties will store a new superProperty, possibly overwriting any existing superProperty with the same name (to set a superProperty only if it is currently unset, use registerSuperPropertiesOnce())
SuperProperties will persist even if your application is taken completely out of memory. to remove a superProperty, call unregisterSuperProperty() or clearSuperProperties()
properties
A Map containing super properties to register
Implementation
void registerSuperProperties(Map<String, dynamic> properties) {
_channel.invokeMethod<void>(
'registerSuperProperties', <String, dynamic>{'properties': properties});
}