@Override
	public boolean isDirectory(File file) {
		return file != null && (FS_ROOT_INFO.isRoot(file) || file.isDirectory());
	}
This is a cache of file icons, as returned from the OS's file icon service.
<p>
This cache is cleared each time a directory is requested (via 
{@link #getListing(File, FileFilter)} so that any changes to a file's icon are visible the 
next time the user hits refresh or navigates into a directory.
Ghidra/Framework/Docking/src/main/java/docking/widgets/filechooser/LocalFileChooserModel.java