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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 append(self, option):
 """ Appends a new `option` to the end of the ButtonGroup. :param string/List option: The option to append to the ButtonGroup. If a 2D list is specified, the first element is the text, the second is the value. """

        self._options.append(self._parse_option(option))
        self._refresh_options()
        self.resize(self._width, self._height)