class_docstr: Test ability to marshall metric protos and invalid input.
class_docstr_tok: ["Test","ability","to","marshall","metric","protos","and","invalid","input","."]
code: def test_invalid_delta_color(self):
      with self.assertRaises(StreamlitAPIException) as exc:
          st.metric("Hello World.", 123, 0, "Invalid")
  
      self.assertEqual(
          "'Invalid' is not an accepted value. delta_color only accepts: "
          "'normal', 'inverse', or 'off'",
          str(exc.exception),
      )
  
imports: from parameterized import parameterized
  import streamlit
  from streamlit.errors import StreamlitAPIException
  from streamlit.proto.LabelVisibilityMessage_pb2 import LabelVisibilityMessage
  from streamlit.proto.Metric_pb2 import Metric
  from streamlit.type_util import _LOGGER
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 14 for calling the MetricTest obj's underlying member method code with example usage: obj.test_invalid_delta_color() without return types