code: def test_parser_roundtrip(self):
      for t in self.types_to_test():
          self.assertEqual(t, dtype(str(t)))
  
imports: from typing import Optional
  import unittest
  from hail.expr import coercer_from_dtype
  from hail.expr.types import *
  from hail.genetics import reference_genome
  from ..helpers import *
  from hail.utils.java import Env
label_desc: Use image node_id 2 for calling the Tests obj's underlying member method code with example usage: obj.test_parser_roundtrip() without return types