(sync
[node ^Duration timeout]
[node ^Date transaction-time ^Duration timeout]
"If the transaction-time is supplied, blocks until indexing has
processed a tx with a greater-than transaction-time, otherwise
blocks until the node has caught up indexing the tx-log
backlog. Will throw an exception on timeout. The returned date is
the latest index time when this node has caught up as of this
call. This can be used as the second parameter in (db valid-time,
transaction-time) for consistent reads.
timeout – max time to wait, can be null for the default.
Returns the latest known transaction time.")