    async def click_stop_button(browser, username):
        """stop the server for one user via the Stop Server button"""
        stop_btn_xpath = f'//a[contains(@href, "user/{username}")]/preceding-sibling::button[contains(@class, "stop-button")]'
        stop_btn = browser.locator(stop_btn_xpath)
        await expect(stop_btn).to_be_enabled()
        await stop_btn.click()
stop the server for one user via the Stop Server button
jupyterhub/tests/browser/test_browser.py