A helpful site responds with an indication that it will never publish, when it knows this outcome for a call.
All library sites in Orc are helpful. Thus,
Ift is a helpful site, and
Ift(false) sends an indication to the caller that it will never
Channel is a helpful site, and some of its methods will send
an indication that they will never publish. In particular, the
method is blocked on an empty channel, but it sends an indication it
will never publish if the channel is closed.
We do not expect arbitrary services to be helpful.