commit method
Append a new entry for key / operation. Returns the
assigned commitId, or -1 for keys that bypass the commit
log (private:, privatekey:, public:_, local:, ...).
opTime is the operation time recorded on the entry: pass a
caller-asserted time (a delete's deletedAt, an update's
asserted updatedAt) when the protocol supplied one; when
null, now. Truncated to millisecond precision. Informational —
entry ordering is by commitId, never by opTime.
Implementation
@override
Future<int?> commit(String key, CommitOp operation,
{DateTime? opTime}) async =>
commitSync(key, operation, opTime: opTime);