code: def test_ctor_with_default_value_none_and_allow_none(self):
      class Example2(HasTraits):
          color1 = UseEnum(Color, default_value=None, allow_none=True)
          color2 = UseEnum(Color, allow_none=True)
  
      example = Example2()
      self.assertIs(example.color1, None)
      self.assertIs(example.color2, None)
  
imports: import enum
  import unittest
  from traitlets import CaselessStrEnum, Enum, FuzzyEnum, HasTraits, TraitError, UseEnum
label_desc: Use image node_id 14 for calling the TestUseEnum obj's underlying member method code with example usage: obj.test_ctor_with_default_value_none_and_allow_none() without return types