docstr: Parameters
  ----------
  selection : PropertySelection, optional
      A PropertySelection returned from one or more calls to
      select_vertices() and/or select_edges()
  
  backend : ('numpy', 'pandas', 'cupy', 'cudf', 'torch', 'torch:<device>')
      Defaults to cudf if available, otherwise falls back to numpy.
  
  Returns
  -------
  Return a Series containing the unique vertex IDs contained in both
  the vertex and edge property data.
code: def get_vertices(self, selection=None, backend="cudf"):
      """
      Parameters
      ----------
      selection : PropertySelection, optional
          A PropertySelection returned from one or more calls to
          select_vertices() and/or select_edges()
  
      backend : ('numpy', 'pandas', 'cupy', 'cudf', 'torch', 'torch:<device>')
          Defaults to cudf if available, otherwise falls back to numpy.
  
      Returns
      -------
      Return a Series containing the unique vertex IDs contained in both
      the vertex and edge property data.
      """
      if selection is not None:
          raise NotImplementedError(
              "Use of get_vertices() with selection"
              " not available for remote property graph."
          )
      vdata = self.__client.get_graph_vertex_data(
          graph_id=self.__graph_id
      )[:, 0]
      return _transform_to_backend_dtype_1d(
          vdata,
          backend=backend,
          dtype="int64",
          series_name=self.vertex_col_name,
      )
  
imports: import numpy
  import importlib
  from cugraph_service_client.exceptions import CugraphServiceError
  from cugraph_service_client.remote_graph_utils import _transform_to_backend_dtype, _transform_to_backend_dtype_1d, _offsets_to_backend_dtype, MissingModule
label_desc: Use image node_id 28 for calling the RemoteGraph obj's underlying member method code with example usage: obj.get_vertices(selection, backend) and returns: _transform_to_backend_dtype_1d