onTeamListUpdate property Null safety

Stream<List<NIMTeam>> onTeamListUpdate

Listen to group profile changes (e.g., the creation of groups and group profile updates). Once the event occurs, a notification about group profile changes will be triggered. observer: The Observer interface, whose parameter is the list of updated group profiles

Implementation

Stream<List<NIMTeam>> get onTeamListUpdate =>
    TeamServicePlatform.instance.onTeamListUpdate.stream;