code: def test_expander_displays_correctly(
      themed_app: Page, assert_snapshot: ImageCompareFunction
  ):
      """Test that sidebar and main container expanders are displayed correctly."""
      # Focus the button, then ensure it's not cut off
      themed_app.locator(".stButton button").first.focus()
      assert_snapshot(
          themed_app.locator(".main"), name="expanders-in-main"
      )
      assert_snapshot(
          themed_app.locator("[data-testid='stSidebar']"),
          name="expanders-in-sidebar",
      )
  
file_path: streamlit/e2e_playwright/st_expander_test.py
imports: from playwright.sync_api import Page, expect
  from e2e_playwright.conftest import ImageCompareFunction, wait_for_app_run
label_desc: Use image node_id 2 for calling a global function with example usage: test_expander_displays_correctly(themed_app, assert_snapshot) without return types