docs: def rcm_vertex_order(vertices_resources, nets):
      """A generator which iterates over the vertices in Reverse-Cuthill-McKee
      order.
  
      For use as a vertex ordering for the sequential placer.
      """
      vertices_neighbours = _get_vertices_neighbours(nets)
      for subgraph_vertices in _get_connected_subgraphs(vertices_resources,
                                                        vertices_neighbours):
          cm_order = _cuthill_mckee(subgraph_vertices, vertices_neighbours)
          for vertex in reversed(cm_order):
              yield vertex