class_docstr: Test torchgen.executorch.api.cpp
code: def _test_returntype_type(
      self, ret_str: str, expected: CType
  ) -> None:
      ret = Return.parse(ret_str)
      self.assertEqual(str(return_type(ret)), str(expected))
  
file_path: pytorch/tools/test/test_executorch_types.py
imports: import unittest
  from torchgen import local
  from torchgen.api.types import BaseCType, ConstRefCType, CType, longT, MutRefCType, NamedCType, OptionalCType, TupleCType, VectorCType, voidT
  from torchgen.executorch.api.et_cpp import argument_type, return_type, returns_type
  from torchgen.executorch.api.types import ArrayRefCType, scalarT, tensorListT, tensorT
  from torchgen.model import Argument, FunctionSchema, Return
label_desc: Use image node_id 3 for calling the ExecutorchCppTest obj's underlying member method code with example usage: obj._test_returntype_type(ret_str, expected) without return types