@TestOnly
  synchronized @NotNull Collection<? extends VirtualFilePointer> getPointersUnder(@NotNull VirtualFileSystemEntry parent, @NotNull String childName) {
    assert !StringUtil.isEmptyOrSpaces(childName);
    @NotNull MultiMap<VirtualFilePointerListener, VirtualFilePointerImpl> nodes = MultiMap.create();
    addRelevantPointers(null, parent, toNameId(childName), nodes, new ArrayList<>(), true, parent.getFileSystem(), new VFileDeleteEvent(this, parent));
    return nodes.values();
  }
@TestOnly
  synchronized @NotNull Collection<? extends VirtualFilePointer> getPointersUnder(@NotNull VirtualFileSystemEntry parent, @NotNull String childName)