code: def test_lazy_import(self):
      # matplotlib.pyplot should be lazily imported because matplotlib.use
      # has to be called earlier.
  
      # To support python2, we do not use self.assertWarns()
      with warnings.catch_warnings(record=True) as w:
          warnings.simplefilter("always")
          matplotlib.use("Agg")
          # Test again with a different backend, because the above does not
          # generate a warning if matplotlib.use('Agg') is called and then
          # matplotlib.pyplot is imported.
          matplotlib.use("PS")
  
      self.assertEqual(len(w), 0)
  
file_path: chainer/tests/chainer_tests/training_tests/extensions_tests/test_plot_report.py
imports: import unittest
  import warnings
  import pytest
  from chainer import testing
  from chainer.training import extensions
label_desc: Use image node_id 2 for calling the TestPlotReport obj's underlying member method code with example usage: obj.test_lazy_import() without return types