private void clearIndexToFirst(){
  for (; ; ) {
    Index<K,V> q=head;
    for (; ; ) {
      Index<K,V> r=q.right;
      if (r != null && r.indexesDeletedNode() && !q.unlink(r))       break;
      if ((q=q.down) == null) {
        if (head.right == null)         tryReduceLevel();
        return;
      }
    }
  }
}

private void clearIndexToFirst ( ) { for ( ; ; ) { Index < K , V > q = head ; for ( ; ; ) { Index < K , V > r = q . right ; if ( r != null && r . indexesDeletedNode ( ) && ! q . unlink ( r ) ) break ; if ( ( q = q . down ) == null ) { if ( head . right == null ) tryReduceLevel ( ) ; return ; } } } }
clears out index nodes associated with deleted first entry .
