code: def test_showwarnings(self):
      self.assertIs(warnings.showwarning, showwarning)
      shell.capture_warnings(True)
      self.assertIs(warnings.showwarning, shell.idle_showwarning)
      shell.capture_warnings(False)
      self.assertIs(warnings.showwarning, showwarning)
  
file_path: catboost/contrib/tools/python/src/Lib/idlelib/idle_test/test_warning.py
imports: import unittest
  from test.test_support import captured_stderr
  import warnings
  from idlelib import run
  from idlelib import PyShell
label_desc: Use image node_id 1 for calling the ShellWarnTest obj's underlying member method code with example usage: obj.test_showwarnings() without return types