*/
void requestDirectoryChildren(
final FileTreeModel fileTreeModel, FileTreeNode node, final NodeRequestCallback callback) {
Preconditions.checkArgument(node.isDirectory(), "Cannot request children of a file");
final PathUtil path = node.getNodePath();
GetDirectoryImpl getDirectory = GetDirectoryImpl.make()
.setPath(path.getPathString())
.setDepth(FrontendConstants.DEFAULT_FILE_TREE_DEPTH)
.setRootId(fileTreeModel.getLastAppliedTreeMutationRevision());
appContext.getFrontendApi().GET_DIRECTORY.send(getDirectory,
new ApiCallback<GetDirectoryResponse>() {