code: def get_composition_admin_session(self):
          
          if not self.supports_composition_admin():
              raise Unimplemented()
          try:
              from . import sessions
          except ImportError:
              raise  # OperationFailed()
          try:
              session = sessions.CompositionAdminSession(proxy=self._proxy,
                                                         runtime=self._runtime)
          except AttributeError:
              raise  # OperationFailed()
          return session
docs: Gets a composition administration session for creating, updating
          and deleting compositions.
  
          return: (osid.repository.CompositionAdminSession) - a
                  CompositionAdminSession
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - supports_composition_admin() is false
          compliance: optional - This method must be implemented if
                      supports_composition_admin() is true.