public static boolean isRootNode(final ExplorerNode node) {
        if (node == null) {
            return false;
        } else {
            return Objects.equals(SYSTEM_NODE, node)
                   || Objects.equals(FAVOURITES_NODE, node);
        }
    }
@return True if node is non-null and one of the root nodes
stroom-core-shared/src/main/java/stroom/explorer/shared/ExplorerConstants.java