code: def plot_montage(
      montage,
      scale_factor=20,
      show_names=True,
      kind="topomap",
      show=True,
      sphere=None,
      *,
      axes=None,
      verbose=None,
  ):
      """Plot a montage.
  
      Parameters
      ----------
      montage : instance of DigMontage
          The montage to visualize.
      scale_factor : float
          Determines the size of the points.
      show_names : bool | list
          Whether to display all channel names. If a list, only the channel
          names in the list are shown. Defaults to True.
      kind : str
          Whether to plot the montage as '3d' or 'topomap' (default).
      show : bool
          Show figure if True.
      %(sphere_topomap_auto)s
      %(axes_montage)s
  
          .. versionadded:: 1.4
      %(verbose)s
  
      Returns
      -------
      fig : instance of matplotlib.figure.Figure
          The figure object.
      """
      from ..channels import DigMontage, make_dig_montage
  
      _check_option("kind", kind, ["topomap", "3d"])
      _validate_type(montage, DigMontage, item_name="montage")
      ch_names = montage.ch_names
      title = None
  
      if len(ch_names) == 0:
          raise RuntimeError("No valid channel positions found.")
  
      pos = np.array(list(montage._get_ch_pos().values()))
  
      dists = cdist(pos, pos)
  
      # only consider upper triangular part by setting the rest to np.nan
      dists[np.tril_indices(dists.shape[0])] = np.nan
      dupes = np.argwhere(np.isclose(dists, 0))
      if dupes.any():
          montage = deepcopy(montage)
          n_chans = pos.shape[0]
          n_dupes = dupes.shape[0]
          idx = np.setdiff1d(np.arange(len(pos)), dupes[:, 1]).tolist()
          logger.info(f"{n_dupes} duplicate electrode labels found:")
          logger.info(
              ", ".join(
                  [ch_names[d[0]] + "/" + ch_names[d[1]] for d in dupes]
              )
          )
          logger.info(f"Plotting {n_chans - n_dupes} unique labels.")
          ch_names = [ch_names[i] for i in idx]
          ch_pos = dict(zip(ch_names, pos[idx, :]))
          # XXX: this might cause trouble if montage was originally in head
          fid, _ = _get_fid_coords(montage.dig)
          montage = make_dig_montage(ch_pos=ch_pos, **fid)
  
      info = create_info(ch_names, sfreq=256, ch_types="eeg")
      info.set_montage(montage, on_missing="ignore")
      fig = plot_sensors(
          info,
          kind=kind,
          show_names=show_names,
          show=show,
          title=title,
          sphere=sphere,
          axes=axes,
      )
      collection = fig.axes[0].collections[0]
      collection.set_sizes([scale_factor])
      return fig
  
imports: from copy import deepcopy
  import numpy
  from scipy.spatial.distance import cdist
  from .._fiff._digitization import _get_fid_coords
  from .._fiff.meas_info import create_info
  from ..utils import _check_option, _validate_type, logger, verbose
  from .utils import plot_sensors
label_desc: Use image node_id 1 for calling a global function with example usage: plot_montage(montage, scale_factor, show_names, kind, show, sphere) and returns: fig