private void updateNode(final DocRef docRef) {
        final ExplorerTreeNode docNode = getNodeForDocRef(docRef).orElse(null);
        if (docNode != null) {
            docNode.setType(docRef.getType());
            docNode.setUuid(docRef.getUuid());
            docNode.setName(docRef.getName());
            explorerTreeDao.update(docNode);
        }
    }
General form a function that returns a list of explorer nodes from the tree DAO

@param folderDocRef  The root doc ref of the query
@param fetchFunction The function to call to get the list of ExplorerTreeNodes given a root ExplorerTreeNode
@return The list of converted ExplorerNodes
stroom-explorer/stroom-explorer-impl/src/main/java/stroom/explorer/impl/ExplorerNodeServiceImpl.java