Taps on a given element.

        :Args:
         - on_element: The element to tap.

def tap(self, on_element):
        """
        Taps on a given element.

        :Args:
         - on_element: The element to tap.
        """
        self._actions.append(lambda: self._driver.execute(
            Command.SINGLE_TAP, {'element': on_element.id}))
        return self