Given a characteristic UUID, return its handle.
    
        Args:
            uuid (str): a string containing the hex-encoded UUID

        Returns:
            None if an error occurs, otherwise an integer handle.

def get_characteristic_handle_from_uuid(self, uuid):
        """Given a characteristic UUID, return its handle.
    
        Args:
            uuid (str): a string containing the hex-encoded UUID

        Returns:
            None if an error occurs, otherwise an integer handle. 
        """
        ch = self.get_characteristic_from_uuid(uuid)
        return None if ch is None else ch.char_handle