A user group can contain users and other user groups (for administrative operations).
  AccessControlList | The definition of the access control list which controls visibility of user group. | 
  ExternalRepositoryName | The identity of the external repository the group is associated with. | 
  ExternalRepositorySubjectID | The identity of the external group this group is associated with. | 
  SemanticAliases | The semantic aliases of this user group. | 
  UserGroup | The user group. |