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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 get_polling_override(self):
 """Get the current polling override value in milliseconds. See :meth:`set_polling_override` for more information. Returns: None on error, otherwise the current override period in milliseconds (0 = disabled). """

        polling_override = self.get_characteristic_handle_from_uuid(UUID_POLLING_OVERRIDE)
        if polling_override is None:
            logger.warn('Failed to find handle for polling override')
            return None
        override_ms = self.dongle._read_attribute(self.conn_handle, polling_override, True)
        return None if override_ms is None else ord(override_ms)