@NotNull
  private VirtualFilePointerContainer registerContainer(
      @NotNull Disposable parent,
      @NotNull final VirtualFilePointerContainerImpl virtualFilePointerContainer) {
    synchronized (myContainers) {
      myContainers.add(virtualFilePointerContainer);
    }
    Disposer.register(
        parent,
        new Disposable() {
          @Override
          public void dispose() {
            Disposer.dispose(virtualFilePointerContainer);
            boolean removed;
            synchronized (myContainers) {
              removed = myContainers.remove(virtualFilePointerContainer);
            }
            if (!ApplicationManager.getApplication().isUnitTestMode()) {
              assert removed;
            }
          }

          @Override
          @NonNls
          @NotNull
          public String toString() {
            return "Disposing container " + virtualFilePointerContainer;
          }
        });
    return virtualFilePointerContainer;
  }
    static void registerDisposable(Disposable parentDisposable, VirtualFilePointerImpl pointer) {
      synchronized (ourInstances) {
        DelegatingDisposable result = ourInstances.get(parentDisposable);
        if (result == null) {
          ourInstances.put(parentDisposable, result = new DelegatingDisposable(parentDisposable));
          Disposer.register(parentDisposable, result);
        }

        result.myCounts.put(pointer, result.myCounts.get(pointer) + 1);
      }
    }
    static void registerDisposable(
        @NotNull Disposable parentDisposable, @NotNull VirtualFilePointerImpl pointer) {
      DelegatingDisposable result = ourInstances.get(parentDisposable);
      if (result == null) {
        DelegatingDisposable newDisposable = new DelegatingDisposable(parentDisposable);
        result = ConcurrencyUtil.cacheOrGet(ourInstances, parentDisposable, newDisposable);
        if (result == newDisposable) {
          Disposer.register(parentDisposable, result);
        }
      }

      synchronized (result) {
        result.myCounts.put(pointer, result.myCounts.get(pointer) + 1);
      }
    }