docs: def _add_job_control_plane(self):
          """
          Add a JobControlPlane operator to the topology, if one has not already
          been added.  If a JobControlPlane operator has already been added,
          this has no effect.
          """
          if not self._has_jcp:
              jcp = self.graph.addOperator(kind="spl.control::JobControlPlane", name="JobControlPlane")
              jcp.viewable = False
              self._has_jcp = True