|AbstractStageTIn, TOutOnUpstreamFailure Method|
Note that elements that were emitted by upstream before the failure happened might not have been received by this stage whenis called, i.e. failures are not backpressured and might be propagated as soon as possible.
Here you cannot call Push(Object), because there might not be any demand from downstream. To emit additional elements before terminating you can use AbsorbTermination and push final elements from OnPull(IContext). The stage will then be in finishing state, which can be checked with IsFinishing.
public abstract ITerminationDirective OnUpstreamFailure( Exception cause, IContext context )
abstract OnUpstreamFailure : cause : Exception * context : IContext -> ITerminationDirective