code: def testInvalidIdentifierField(self):
      with self.assertRaisesRegexp(
          ValueError, "Field names must be valid identifiers: 0"
      ):
          structural_tuple.structtuple(["0"])
  
imports: import tensorflow.compat.v2
  from tensorflow_probability.python.internal import nest_util
  from tensorflow_probability.python.internal import structural_tuple
  from tensorflow_probability.python.internal import test_util
  from tensorflow.python.util import nest
label_desc: Use image node_id 11 for calling the StructTupleTest obj's underlying member method code with example usage: obj.testInvalidIdentifierField() without return types