InvitationMessage constructor
      
      InvitationMessage({})
     
    
    
Implementation
InvitationMessage(
    {required String id,
    required MessageType type,
    String? fromId,
    String? fromName,
    this.fromAvatar,
    this.text,
    int? sendTime})
    : super(
          id: id,
          type: type,
          fromId: fromId,
          fromName: fromName,
          sendTime: sendTime);