Folds events (the tail after from.head) onto a checkpoint, or onto the initial state. Fold in local order (Feed.getLocalCursor): it never changes under a reader, so a checkpoint stays valid as sync repositions the feed.
events
from.head
Feed.getLocalCursor
Optional
Folds
events(the tail afterfrom.head) onto a checkpoint, or onto the initial state. Fold in local order (Feed.getLocalCursor): it never changes under a reader, so a checkpoint stays valid as sync repositions the feed.