code: def test_cull_markers():
      x = np.random.random(20000)
      y = np.random.random(20000)
  
      fig, ax = plt.subplots()
      ax.plot(x, y, "k.")
      ax.set_xlim(2, 3)
  
      pdf = io.BytesIO()
      fig.savefig(pdf, format="pdf")
      assert len(pdf.getvalue()) < 8000
  
      svg = io.BytesIO()
      fig.savefig(svg, format="svg")
      assert len(svg.getvalue()) < 20000
  
imports: import io
  from itertools import chain
  import numpy
  import pytest
  import matplotlib.colors
  import matplotlib.pyplot
  import matplotlib.patches
  import matplotlib.lines
  import matplotlib.path
  import matplotlib.transforms
  import matplotlib.collections
  import matplotlib.artist
  import matplotlib.backend_bases
  import matplotlib
  from matplotlib.testing.decorators import check_figures_equal, image_comparison
label_desc: Use image node_id 5 for calling a global function with example usage: test_cull_markers() without return types