class_docstr: Test ability to marshall date_input protos.
class_docstr_tok: ["Test","ability","to","marshall","date_input","protos","."]
docstr: Test that it can be called with None as value.
docstr_tok: ["Test","that","it","can","be","called","with","None","as","value","."]
code: def test_none_value(self):
      """Test that it can be called with None as value."""
      st.date_input("the label", value=None)
  
      c = self.get_delta_from_queue().new_element.date_input
      self.assertEqual(c.label, "the label")
      # If a proto property is null is not determined by this value,
      # but by the check via the HasField method:
      self.assertEqual(c.default, [])
  
imports: from datetime import date, datetime, timedelta
  from parameterized import parameterized
  from pytest import raises
  import streamlit
  from streamlit.errors import StreamlitAPIException
  from streamlit.proto.LabelVisibilityMessage_pb2 import LabelVisibilityMessage
  from streamlit.testing.v1.app_test import AppTest
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 3 for calling the DateInputTest obj's underlying member method code with example usage: obj.test_none_value() without return types