code: def test_blended():
      fig, ax = plt.subplots()
      ax.axvline(0)
  
imports: import matplotlib
  import numpy
  import pytest
  from numpy.testing import assert_warns
  from packaging.version import Version
  from ..exporter import Exporter
  from ..renderers import FakeRenderer, FullFakeRenderer
  from .None import plt
label_desc: Use image node_id 13 for calling a global function with example usage: test_blended() without return types