code: def test_optional_types(self):
      class InputOptionalTypes(Typing):
          @property
          def input_types(self):
              return {
                  "x": NeuralType(("B",), ElementType()),
                  "y": NeuralType(("B",), ElementType(), optional=True),
              }
  
          @typecheck()
          def __call__(self, x, y=None):
              if y is None:
                  x += 1
              else:
                  x += y
              return x
  
      obj = InputOptionalTypes()
      result = obj(x=torch.zeros(10))
  
      assert result.sum() == torch.tensor(10.0)
      assert hasattr(result, "neural_type") is False
  
      result2 = obj(
          x=torch.zeros(10),
          y=torch.full([10], fill_value=5, dtype=torch.int32),
      )
  
      assert result2.sum() == torch.tensor(10 * 5)
      assert hasattr(result, "neural_type") is False
  
imports: from typing import List, NamedTuple
  import pytest
  import torch
  from nemo.core import Typing, typecheck
  from nemo.core.neural_types import *
label_desc: Use image node_id 16 for calling the TestNeuralTypeCheckSystem obj's underlying member method code with example usage: obj.test_optional_types() and returns: dict, x