readTail

The streams of ref from fromVersion on, in version order (facts only, as read gives them), and the request keys of its latest streams before fromVersion, at most earlier of them, the latest first, read in one round trip where the backend can: a kernel loading an aggregate from its snapshot reads the tail after it together with the requests it most recently committed, so the next command need not look its request id up. The keys are taken by version alone, whenever they committed; fewer than earlier means none is left before them. By default, two reads.