code: def test_generator(self):
      def f(a=1, /, b=2):
          yield a, b
  
      with self.assertRaisesRegex(
          TypeError,
          r"f\(\) got some positional-only arguments passed as keyword arguments: 'a'",
      ):
          f(a=1, b=2)
  
      gen = f(1, 2)
      self.assertEqual(next(gen), (1, 2))
      gen = f(1, b=2)
      self.assertEqual(next(gen), (1, 2))
      gen = f(1)
      self.assertEqual(next(gen), (1, 2))
      gen = f()
      self.assertEqual(next(gen), (1, 2))
  
imports: import dis
  import pickle
  import unittest
  from test.support import check_syntax_error
label_desc: Use image node_id 27 for calling the PositionalOnlyTestCase obj's underlying member method code with example usage: obj.test_generator() without return types