code: public static <V> Node<V> findNodeByLabel(List<Node<V>> parents, String labelPrefix) {
          return findNode(parents, new LabelPrefixPredicate<V>(labelPrefix));
      }
docs: Returns the first node underneath the given parents which matches the given label prefix.
  If parents is null or empty or no node is found the method returns null.
  
  @param parents     the parent Nodes to look through
  @param labelPrefix the label prefix to look for
  @return the Node if found or null if not found