docstr: Test that it can be called with no params
docstr_tok: ["Test","that","it","can","be","called","with","no","params"]
code: def test_just_label(self):
      """Test that it can be called with no params"""
      expander = st.expander("label")
  
      with expander:
          pass
  
      expander_block = self.get_delta_from_queue()
      self.assertEqual(
          expander_block.add_block.expandable.label, "label"
      )
      self.assertEqual(
          expander_block.add_block.expandable.expanded, False
      )
  
imports: import streamlit
  from streamlit.errors import StreamlitAPIException
  from tests.delta_generator_test_case import DeltaGeneratorTestCase
label_desc: Use image node_id 2 for calling the ExpanderTest obj's underlying member method code with example usage: obj.test_just_label() without return types