Materializes to IFlowMonitor that allows monitoring of the the current flow. All events are propagated by the monitor unchanged. Note that the monitor inserts a memory barrier every time it processes an event, and may therefor affect performance. The combine function is used to combine the IFlowMonitor with this flow's materialized value.

public static Source<TOut, TMat2> Monitor<TOut, TMat, TMat2>(
	this Source<TOut, TMat> flow,
	Func<TMat, IFlowMonitor, TMat2> combine
)

[<ExtensionAttribute>]
static member Monitor : 
        flow : Source<'TOut, 'TMat> * 
        combine : Func<'TMat, IFlowMonitor, 'TMat2> -> Source<'TOut, 'TMat2>