code: public static <A, N extends Node<A,?,N>>  List<A> recoverActionPath(N node){
          List<A> actions = new LinkedList<A>();
          for(N n : node.path()){
              if (n.action() != null) actions.add(n.action());
          }
          return actions;
      }
docs: Returns a path of the actions applied from the initial state
  to the state of the provided node ({@link es.usc.citius.hipster.model.Node#state()}).
  
  @param <A> type of the actions.
  @param <N> type of the nodes.
  @return list with the ordered actions.