code: def test_switch_backend_no_close():
      plt.switch_backend("agg")
      fig = plt.figure()
      fig = plt.figure()
      assert len(plt.get_fignums()) == 2
      plt.switch_backend("agg")
      assert len(plt.get_fignums()) == 2
      with pytest.warns(mpl.MatplotlibDeprecationWarning):
          plt.switch_backend("svg")
      assert len(plt.get_fignums()) == 0
  
imports: import difflib
  import numpy
  import sys
  from pathlib import Path
  import pytest
  import matplotlib
  from matplotlib.testing import subprocess_run_for_testing
  from matplotlib import pyplot
label_desc: Use image node_id 25 for calling a global function with example usage: test_switch_backend_no_close() without return types