private boolean checkCleanInstall() {
		ResourceFile[] files = appLayout.getExtensionInstallationDirs().get(0).listFiles();
		return (files == null || files.length == 0);
	}
Tests for the {@link ExtensionInstaller} class.
Ghidra/Framework/Project/src/test/java/ghidra/framework/project/extensions/ExtensionInstallerTest.java