class_docstr: Test ability to marshall subheader protos.
docstr: Test st.subheader with invalid divider.
docstr_tok: ["Test","st.subheader","with","invalid","divider","."]
code: def test_st_subheader_with_invalid_divider(self):
      """Test st.subheader with invalid divider."""
      with pytest.raises(StreamlitAPIException):
          st.subheader("some header", divider="corgi")
  
imports: import pytest
  import streamlit
  from streamlit.errors import StreamlitAPIException
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 8 for calling the StSubheaderTest obj's underlying member method code with example usage: obj.test_st_subheader_with_invalid_divider() without return types