Flatten the sub-flows back into the super-flow by performing a merge with the given parallelism limit. This means that only up to parallelism substreams will be executed at any given time. Substreams that are not yet executed are also not materialized, meaning that back-pressure will be exerted at the operator that creates the substreams when the parallelism limit is reached.

public abstract IFlow<TOut, TMat> MergeSubstreamsWithParallelism(
	int parallelism
)

abstract MergeSubstreamsWithParallelism : 
        parallelism : int -> IFlow<'TOut, 'TMat>