public RepositoryFolder getFolder(String folderName) {
		synchronized (fileSystem) {
			RepositoryFolder rf = folderMap.get(folderName);
			if (rf != null) {
				return rf;
			}
// TODO: Could be a problem for root folder whose pathname is '/'
			String path = makePathname(getPathname(), folderName);
			if (fileSystem.folderExists(path)) {
				try {
					rf = new RepositoryFolder(repository, fileSystem, this, folderName);
					folderMap.put(folderName, rf);
					return rf;
				}
				catch (IOException e) {
					log.error("Repository error: " + repository.getName() + ": " + e.getMessage());
				}
			}
			return null;
		}
	}
Returns sub-folders with the specified name or null 
if sub-folder not found within this folder.
@param folderName sub-folder name
@return specified sub-folder or null if not found
Ghidra/Features/GhidraServer/src/main/java/ghidra/server/store/RepositoryFolder.java