code: def surface_is_valid1(surface):
      
      if NO_IMAGES:
          return
  
      ax = surface.plot(256)
      ax.axis("scaled")
      ax.set_xlim(-0.125, 2.125)
      ax.set_ylim(-0.125, 2.125)
      save_image(ax.figure, "surface_is_valid1.png")
docs: Image for :meth`.Surface.is_valid` docstring.