code: def test_warn_to_fail():
      warnings.warn("This should fail the test")
  
file_path: matplotlib/lib/matplotlib/tests/test_testing.py
imports: import warnings
  import pytest
  import matplotlib.pyplot
  from matplotlib.testing.decorators import check_figures_equal
label_desc: Use image node_id 1 for calling a global function with example usage: test_warn_to_fail() without return types