public <T extends ExternalSystemNode> void visitExistingNodes(@NotNull Class<? extends T> nodeClass,
                                                                @NotNull Consumer<? super T> consumer) {
    for (T node : getExistingNodes(nodeClass)) {
      consumer.consume(node);
    }
  }
public <T extends ExternalSystemNode> void visitExistingNodes(@NotNull Class<? extends T> nodeClass,
                                                                @NotNull Consumer<? super T> consumer)