ChangeReason
        
        Description:
        public enum ChangeReason
        
        
          The reason a group member has changed its membership in the group.
          These closely follow the 
            
              Channel_Group_Change_Reason interface in the Telepathy specification.
         
        Content:
        Enum values:
        
          - BANNED - The change is due 
              to a kick+ban operation.
- BUSY - The change is due to a 
              busy indication.
- ERROR - The change is due to 
              an error occurring.
- INVALID_MEMBER - The
              change is because the requested member does not exist.
- INVITED - The change is due
              to an invitation.
- KICKED - The change is due 
              to a kick operation.
- NONE - No reason was provided 
              for this change.
- NO_ANSWER - The change is
              because the requested contact did not respond.
- OFFLINE - The change is due
              to a member going offline.
- PERMISSION_DENIED - 
            The change is because there was no permission to contact the requested member.
- RENAMED - The change is 
              because a member's unique identifier changed.
- SEPARATED - If members 
              are removed with this reason code, the change is because the group has split into unconnected parts which can only communicate within 
              themselves (e.g. netsplits on IRC use this reason code).