public static List<File> getUserSettingsFiles(String dirName, String fileExtension) {
		File userSettingsDir = getUserSettingsDirectory();
		File subSettingsDir = new File(userSettingsDir, dirName);
		FileFilter filter = f -> f.getName().endsWith(fileExtension);

		if (!subSettingsDir.exists()) {
			subSettingsDir.mkdir();
			copyFilesFromPreviousVersion(subSettingsDir, dirName, filter);
		}
		File[] files = subSettingsDir.listFiles(filter);
		return CollectionUtils.asList(files);
	}
Returns a list of files in a setting subdirectory that have the given file extension,
copying files from older versions of Ghidra if the settings dir is not yet established.
@param dirName the name of the settings subdirectory.
@param fileExtension the file name suffix
@return a list of files in a setting sub directory that have the given file extension
Ghidra/Framework/Generic/src/main/java/ghidra/framework/Application.java