synchronized public long findNext(final long timestamp){
  if (timestamp < 0L)   throw new IllegalArgumentException();
  final long index=findIndexOf(Math.abs(timestamp)) + 1;
  if (index == nentries) {
    return -1L;
  }
  return decodeKey(keyAt(index));
}

synchronized public long findNext ( final long timestamp ) { if ( timestamp < 0L ) throw new IllegalArgumentException ( ) ; final long index = findIndexOf ( Math . abs ( timestamp ) ) + 1 ; if ( index == nentries ) { return - 1L ; } return decodeKey ( keyAt ( index ) ) ; }
find the first commit time strictly greater than the timestamp .
