public RepositoryFile getFile(String fileName) {
		synchronized (fileSystem) {
			RepositoryFile rf = fileMap.get(fileName);
			if (rf != null) {
				return rf;
			}
			// NOTE: Uncertain what condition would lead to exiting file not already
			// existing in fileMap
			if (fileSystem.fileExists(getPathname(), fileName)) {
				try {
					LocalFolderItem item = fileSystem.getItem(getPathname(), fileName);
					if (item == null || !(item instanceof DatabaseItem)) {
						log.error("Repository '" + repository.getName() + "' contains bad item: " +
							makePathname(getPathname(), fileName));
						return null;
					}
					rf = new RepositoryFile(repository, fileSystem, this, fileName);
					fileMap.put(fileName, rf);
					return rf;
				}
				catch (IOException e) {
					log.error("Repository '" + repository.getName() + "' file error: " +
						e.getMessage() + "\n    " + makePathname(getPathname(), fileName));
				}
			}
			return null;
		}
	}
Returns files/items with the specified name or null 
if file/item not found within this folder.
@param fileName sub-folder name
@return named file or null if not found
Ghidra/Features/GhidraServer/src/main/java/ghidra/server/store/RepositoryFolder.java