default GFile getRootDir() {
		try {
			return lookup(null);
		}
		catch (IOException e) {
			return null;
		}
	}
Returns the file system's root directory.
<p>
Note: using {@code null} when calling {@link #getListing(GFile)} is also valid.

@return file system's root directory
Ghidra/Features/Base/src/main/java/ghidra/formats/gfilesystem/GFileSystem.java