class_docstr: Test ability to marshall metric protos and invalid input.
class_docstr_tok: ["Test","ability","to","marshall","metric","protos","and","invalid","input","."]
docstr: Test that a warning is logged if st.metric was called with empty label.
docstr_tok: ["Test","that","a","warning","is","logged","if","st.metric","was","called","with","empty","label","."]
code: def test_empty_label_warning(self):
      """Test that a warning is logged if st.metric was called with empty label."""
  
      with self.assertLogs(_LOGGER) as logs:
          st.metric(label="", value="123")
  
      self.assertIn(
          "`label` got an empty value. This is discouraged for accessibility reasons",
          logs.records[0].msg,
      )
  
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 11 for calling the MetricTest obj's underlying member method code with example usage: obj.test_empty_label_warning() without return types