code: def plot_wigner_seitz(lattice, ax=None, **kwargs):
      
      ax, fig, plt = get_ax3d_fig_plt(ax)
  
      if "color" not in kwargs:
          kwargs["color"] = "k"
      if "linewidth" not in kwargs:
          kwargs["linewidth"] = 1
  
      bz = lattice.get_wigner_seitz_cell()
      ax, fig, plt = get_ax3d_fig_plt(ax)
      for iface in range(len(bz)):
          for line in itertools.combinations(bz[iface], 2):
              for jface in range(len(bz)):
                  if iface < jface and any(
                          np.all(line[0] == x) for x in bz[jface]) \
                          and any(np.all(line[1] == x) for x in bz[jface]):
                      ax.plot(*zip(line[0], line[1]), **kwargs)
  
      return fig, ax
docs: Adds the skeleton of the Wigner-Seitz cell of the lattice to a matplotlib Axes
  
      Args:
          lattice: Lattice object
          ax: matplotlib :class:`Axes` or None if a new figure should be created.
          kwargs: kwargs passed to the matplotlib function 'plot'. Color defaults to black
              and linewidth to 1.
  
      Returns:
          matplotlib figure and matplotlib ax