}

    /**
     * Disposes of all registered resources.
     */
    public static synchronized void dispose() {
        while (!disposables.isEmpty()) {
            final Disposable disposable = disposables.removeLast();
            try {
                disposable.dispose();
            } catch (final Throwable t) {

                    List<String> ret = visitCycle(graph, graph.get(v), stateMap, cycle);
                    if (ret != null) {
                        return ret;
                    }
                    cycle.removeLast();
                    stateMap.put(v, DfsState.VISITED);
                } else if (state == DfsState.VISITING) {
                    // we are already visiting this vertex, this mean we have a cycle

            } catch (Exception e) {
                throw new ClassDocGenerationException("Could not load the class documentation for class '$className'.", e)
            }
        } finally {
            currentlyBuilding.removeLast()
        }
    }

    private File getFileForClass(String className) {
        File classFile = new File(classDocbookDir, "${className}.xml")
        classFile
    }

                cycle.addLast(v.label);
                List<String> ret = visitCycle(v.children, stateMap, cycle);
                if (ret != null) {
                    return ret;
                }
                cycle.removeLast();
                stateMap.put(v, DfsState.VISITED);
            } else if (state == DfsState.VISITING) {
                // we are already visiting this vertex, this mean we have a cycle

    stack.addLast(new NodeAndRemainingSuccessors<>(startNode));

    while (!stack.isEmpty()) {
      // To peek at the top two items, we need to temporarily remove one.
      NodeAndRemainingSuccessors<N> top = stack.removeLast();
      NodeAndRemainingSuccessors<N> prev = stack.peekLast();
      stack.addLast(top);

      N node = top.node;
      N previousNode = prev == null ? null : prev.node;

    }

    /**
     * @throws Exception
     */
    @Test
    public void testRemoveLast() throws Exception {
        list.addLast("1");
        list.addLast("2");
        list.removeLast();
        assertThat(list.getLast(), is("1"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testAddFirst() throws Exception {
        list.addFirst("1");

    Deque<Spliterator<T>> splits = new ArrayDeque<>();
    splits.addLast(stream.spliterator());

    while (!splits.isEmpty()) {
      Spliterator<T> spliterator = splits.removeLast();

      if (spliterator.getExactSizeIfKnown() == 0) {
        continue; // drop this split
      }

      // Many spliterators will have trySplits that are SUBSIZED even if they are not themselves

    Deque<Spliterator<T>> splits = new ArrayDeque<>();
    splits.addLast(stream.spliterator());

    while (!splits.isEmpty()) {
      Spliterator<T> spliterator = splits.removeLast();

      if (spliterator.getExactSizeIfKnown() == 0) {
        continue; // drop this split
      }

      // Many spliterators will have trySplits that are SUBSIZED even if they are not themselves

          if (topConcat.metaIterators != null) {
            while (!topConcat.metaIterators.isEmpty()) {
              this.metaIterators.addFirst(topConcat.metaIterators.removeLast());
            }
          }
          this.topMetaIterator = topConcat.topMetaIterator;
        }
      }
      return true;
    }

    @Override
    @ParametricNullness

          if (topConcat.metaIterators != null) {
            while (!topConcat.metaIterators.isEmpty()) {
              this.metaIterators.addFirst(topConcat.metaIterators.removeLast());
            }
          }
          this.topMetaIterator = topConcat.topMetaIterator;
        }
      }
      return true;
    }

    @Override
    @ParametricNullness