code: def test_markevery_figure_line_unsupported_relsize():
      fig = plt.figure()
      fig.add_artist(
          mlines.Line2D([0, 1], [0, 1], marker="o", markevery=0.5)
      )
      with pytest.raises(ValueError):
          fig.canvas.draw()
  
imports: import itertools
  import platform
  import timeit
  from types import SimpleNamespace
  from cycler import cycler
  import numpy
  from numpy.testing import assert_array_equal
  import pytest
  import matplotlib
  import matplotlib
  from matplotlib import _path
  import matplotlib.lines
  from matplotlib.markers import MarkerStyle
  from matplotlib.path import Path
  import matplotlib.pyplot
  import matplotlib.transforms
  from matplotlib.testing.decorators import image_comparison, check_figures_equal
label_desc: Use image node_id 21 for calling a global function with example usage: test_markevery_figure_line_unsupported_relsize() without return types