def stopFlow():
    """
        End the flow from this L{IFount}; after this invocation, this L{IFount}
        should never call any methods on its C{drain} other than
        L{self.drain.flowStopped() <IDrain.flowStopped>}.  It will invoke
        C{flowStopped} once, when the resources associated with this L{IFount}
        flowing have been released.
        """
