Click on a HTML element with a given tooltip.

    This is very useful if you're clicking on icon buttons, etc.

def press_by_tooltip(self, tooltip):
    """
    Click on a HTML element with a given tooltip.

    This is very useful if you're clicking on icon buttons, etc.
    """
    for button in find_by_tooltip(world.browser, tooltip):
        try:
            button.click()
            break
        except:  # pylint:disable=bare-except
            pass
    else:
        raise AssertionError("No button with tooltip '{0}' found"
                             .format(tooltip))