code: @Path("connectionGroups")
      public DirectoryResource<ConnectionGroup, APIConnectionGroup> getConnectionGroupDirectoryResource()
              throws GuacamoleException {
          return connectionGroupDirectoryResourceFactory.create(userContext,
                  userContext.getConnectionGroupDirectory());
      }
docs: Returns a new resource which represents the ConnectionGroup Directory
  contained within the UserContext exposed by this UserContextResource.
  
  @return
  A new resource which represents the ConnectionGroup Directory
  contained within the UserContext exposed by this UserContextResource.
  
  @throws GuacamoleException
  If an error occurs while retrieving the ConnectionGroup Directory.