code: def test_bad_f_has_keyword_arg(self):
      with self.assertRaisesRegex(ValueError, "keyword arg"):
          _ = tl.Fn("", lambda x, **kwargs: x)
  
imports: from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from trax import fastmath
  from trax import shapes
  from trax.fastmath import numpy
  import trax.layers
label_desc: Use image node_id 2 for calling the FnTest obj's underlying member method code with example usage: obj.test_bad_f_has_keyword_arg() without return types