final Node<K,V> findFirst(){
  for (Node<K,V> b, n; ; ) {
    if ((n=(b=head.node).next) == null)     return null;
    if (n.value != null)     return n;
    n.helpDelete(b,n.next);
  }
}

final Node < K , V > findFirst ( ) { for ( Node < K , V > b , n ; ; ) { if ( ( n = ( b = head . node ) . next ) == null ) return null ; if ( n . value != null ) return n ; n . helpDelete ( b , n . next ) ; } }
specialized variant of findnode to get first valid node .
