public synchronized void purge() {
		for (File f : cacheDir.listFiles()) {
			String name = f.getName();
			if (f.isDirectory() && NESTING_DIR_NAME_REGEX.matcher(name).matches()) {
				FileUtilities.deleteDir(f);
			}
		}
		memCache.clear();
	}
Deletes all stored files from this file cache that are under a "NN" two hex digit
nesting dir.
<p>
Will cause other processes which are accessing or updating the cache to error.
Ghidra/Features/Base/src/main/java/ghidra/formats/gfilesystem/FileCache.java