Convenience method for executing the callable `func` as a transaction
        while watching all keys specified in `watches`. The 'func' callable
        should expect a single arguement which is a Pipeline object.

def transaction(self, func, *watches, **kwargs):
        """
        Convenience method for executing the callable `func` as a transaction
        while watching all keys specified in `watches`. The 'func' callable
        should expect a single arguement which is a Pipeline object.
        """
        with self.pipeline(True, share_in_threads=kwargs.get('share_in_threads', False)) as pipe:
            while 1:
                try:
                    if watches:
                        pipe.watch(*watches)
                    func(pipe)
                    return pipe.execute()
                except WatchError:
                    continue