code: def drop_shadow_line(ax):
      # copied from examples/misc/svg_filter_line.py
  
      # draw lines
      (l1,) = ax.plot([0.1, 0.5, 0.9], [0.1, 0.9, 0.5], "bo-")
      (l2,) = ax.plot([0.1, 0.5, 0.9], [0.5, 0.2, 0.7], "ro-")
  
      gauss = DropShadowFilter(4)
  
      for l in [l1, l2]:
          # draw shadows with same lines with slight offset.
          xx = l.get_xdata()
          yy = l.get_ydata()
          (shadow,) = ax.plot(xx, yy)
          shadow.update_from(l)
  
          # offset transform
          transform = mtransforms.offset_copy(
              l.get_transform(),
              ax.figure,
              x=4.0,
              y=-6.0,
              units="points",
          )
          shadow.set_transform(transform)
  
          # adjust zorder of the shadow lines so that it is drawn below the
          # original lines
          shadow.set_zorder(l.get_zorder() - 0.5)
          shadow.set_agg_filter(gauss)
          shadow.set_rasterized(True)  # to support mixed-mode renderers
  
      ax.set_xlim(0.0, 1.0)
      ax.set_ylim(0.0, 1.0)
  
      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 4 for calling a global function with example usage: drop_shadow_line(ax) without return types