public String execute() throws Exception {
MongoCommit fromCommit = new FetchCommitAction(
nodeStore, fromRevision).execute();
MongoCommit toCommit = new FetchCommitAction(
nodeStore, toRevision).execute();
FetchNodesActionNew action = new FetchNodesActionNew(
nodeStore, path, 0, fromRevision);
action.setBranchId(fromCommit.getBranchId());
NodeImpl fromNode = MongoNode.toNode(action.execute().get(path));
action = new FetchNodesActionNew(
nodeStore, path, 0, toRevision);
action.setBranchId(toCommit.getBranchId());
NodeImpl toNode = MongoNode.toNode(action.execute().get(path));
String diff = "";
if (!fromNode.getRevisionId().equals(toNode.getRevisionId())) {
// diff of node at given path
DiffBuilder diffBuilder = new DiffBuilder(MongoUtil.wrap(fromNode),