code: def display_colorbar():
      """Display a correct numeric colorbar for a shaded plot."""
      y, x = np.mgrid[-4:2:200j, -4:2:200j]
      z = 10 * np.cos(x**2 + y**2)
  
      cmap = plt.cm.copper
      ls = LightSource(315, 45)
      rgb = ls.shade(z, cmap)
  
      fig, ax = plt.subplots()
      ax.imshow(rgb, interpolation="bilinear")
  
      # Use a proxy artist for the colorbar...
      im = ax.imshow(z, cmap=cmap)
      im.remove()
      fig.colorbar(im, ax=ax)
  
      ax.set_title(
          "Using a colorbar with a shaded plot", size="x-large"
      )
  
imports: import matplotlib.pyplot
  import numpy
  from matplotlib.colors import LightSource, Normalize
label_desc: Use image node_id 1 for calling a global function with example usage: display_colorbar() without return types