code: def test_serialize_date(self):
      date = dt.date(1900, 2, 18)
      expected = {"year": 1900, "month": 1, "date": 18}
      self.assertEqual(self.to_json(date, self.dummy_manager), expected)
  
imports: import array
  import datetime
  import pytest
  from unittest import TestCase
  from traitlets import HasTraits, Int, TraitError
  from traitlets.tests.test_traitlets import TraitTestBase
  from ipywidgets import Color, NumberFormat
  from ipywidgets.widgets.widget import _remove_buffers, _put_buffers
  from ipywidgets.widgets.trait_types import date_serialization, TypedTuple
label_desc: Use image node_id 3 for calling the TestDateSerialization obj's underlying member method code with example usage: obj.test_serialize_date() without return types