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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def alt_click(self, locator, params=None, timeout=None):
 """ Alt-click web element. :param locator: locator tuple or WebElement instance :param params: (optional) locator parameters :param timeout: (optional) time to wait for element :return: None """

        self._click(locator, params, timeout, Keys.ALT)