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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 path(self, value=None):
 """ Return or set the path :param string value: the new path to use :returns: string or new :class:`URL` instance """

        if value is not None:
            if not value.startswith('/'):
                value = '/' + value
            encoded_value = unicode_quote(value)
            return URL._mutate(self, path=encoded_value)
        return self._tuple.path