question: public T findByCommitCounter ( final long commitCounter ) { if ( commitCounter < 0L ) throw new IllegalArgumentException ( ) ; final Lock lock = readLock ( ) ; lock . lock ( ) ; try { @ SuppressWarnings ( "unchecked" ) final ITupleIterator < T > itr = rangeIterator ( null , null , 0 , IRangeQuery . DEFAULT | IRangeQuery . REVERSE , null ) ; while ( itr . hasNext ( ) ) { final ITuple < T > t = itr . next ( ) ; final T r = t . getObject ( ) ; final IRootBlockView rb = r . getRootBlock ( ) ; if ( rb . getCommitCounter ( ) <= commitCounter ) { return r ; } } return null ; } finally { lock . unlock ( ) ; } }
target:  Find the oldest entry whose commit counter is LTE the specified commit counter.