private void recordNodeTags(final ExplorerNode... explorerNodes) {
        if (explorerNodes != null) {
            for (final ExplorerNode explorerNode : explorerNodes) {
                if (explorerNode != null) {
                    final Set<String> tags = explorerNode.getTags();
                    if (NullSafe.hasItems(tags)) {
                        allTags.addAll(tags);
                    }
                }
            }
        }
    }
Should only be called after all calls to {@link AbstractTreeModel#add(ExplorerNode, ExplorerNode)}
have been made so all nodes are available
stroom-explorer/stroom-explorer-impl/src/main/java/stroom/explorer/impl/AbstractTreeModel.java