OptionalcontextOpaque caller state (e.g. view path and selection) handed back on undo and redo.
OptionalmergeEntries with equal scope and merge key recorded within the merge window fold together.
OptionalmessageMessage describing the entry (toast label).
OptionalscopeDocument or subject the entry belongs to; undefined entries are reachable only by unscoped undo/redo.
Steps in forward order; undo runs their inverses in reverse order.
Time the entry was first recorded.
Time the entry last absorbed an invocation; the merge window slides from here.
History entry stored by HistoryTracker: a single invocation, a merged run of invocations, or a transaction.