code: def drop_shadow_patches(ax):
      # Copied from barchart_demo.py
      N = 5
      group1_means = [20, 35, 30, 35, 27]
  
      ind = np.arange(N)  # the x locations for the groups
      width = 0.35  # the width of the bars
  
      rects1 = ax.bar(ind, group1_means, width, color="r", ec="w", lw=2)
  
      group2_means = [25, 32, 34, 20, 25]
      rects2 = ax.bar(
          ind + width + 0.1,
          group2_means,
          width,
          color="y",
          ec="w",
          lw=2,
      )
  
      drop = DropShadowFilter(5, offsets=(1, 1))
      shadow = FilteredArtistList(rects1 + rects2, drop)
      ax.add_artist(shadow)
      shadow.set_zorder(rects1[0].get_zorder() - 0.1)
  
      ax.set_ylim(0, 40)
  
      ax.xaxis.set_visible(False)
      ax.yaxis.set_visible(False)
  
imports: import matplotlib.pyplot
  import numpy
  from matplotlib.artist import Artist
  import matplotlib.cm
  from matplotlib.colors import LightSource
  import matplotlib.transforms
label_desc: Use image node_id 5 for calling a global function with example usage: drop_shadow_patches(ax) without return types