@NotNull
  private MultiMap<RemoveConfigurableHandler, MyNode> groupNodes(List<? extends MyNode> nodes) {
    List<? extends RemoveConfigurableHandler<?>> handlers = getRemoveHandlers();
    MultiMap<RemoveConfigurableHandler, MyNode> grouped = MultiMap.createLinked();
    for (MyNode node : nodes) {
      final NamedConfigurable<?> configurable = node.getConfigurable();
      if (configurable == null) continue;
      RemoveConfigurableHandler handler = findHandler(handlers, configurable.getClass());
      if (handler == null) continue;

      grouped.putValue(handler, node);
    }
    return grouped;
  }
@NotNull
  private MultiMap<RemoveConfigurableHandler, MyNode> groupNodes(List<? extends MyNode> nodes)