code: def press_by_tooltip(step, tooltip):
      
      with AssertContextManager(step):
          for button in world.browser.find_elements_by_xpath(str(
              '//*[@title="%(tooltip)s" or @data-original-title="%(tooltip)s"]' %
                  dict(tooltip=tooltip))):
              try:
                  button.click()
                  break
              except Exception:
                  pass
          else:
              raise AssertionError("No button with tooltip '{0}' found"
                                   .format(tooltip))
docs: Press a button having a given tooltip.