class_docstr: Test form submit button.
class_docstr_tok: ["Test","form","submit","button","."]
docstr: Test that a submit button does not use_use_container width by default.
code: def test_submit_button_does_not_use_container_width_by_default(self):
      """Test that a submit button does not use_use_container width by default."""
  
      form = st.form("foo")
      form.form_submit_button(type="primary")
  
      last_delta = self.get_delta_from_queue()
      self.assertFalse(
          last_delta.new_element.button.use_container_width
      )
  
imports: from unittest.mock import MagicMock, patch
  import streamlit
  from streamlit.errors import StreamlitAPIException
  from streamlit.runtime.state.session_state import RegisterWidgetResult
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 8 for calling the FormSubmitButtonTest obj's underlying member method code with example usage: obj.test_submit_button_does_not_use_container_width_by_default() without return types