private Node < K , V > leastValidNode ( final Node < K , V > node , final int index , final String thread_id ) { Node < K , V > lval = node ; while ( lval != null && ! validNode ( lval , thread_id ) ) { lval = nextSmaller ( lval , index ) ; } return lval ; }
find the least valid node from a given node . very useful for starting a sorting iterator ...