@Override
	public boolean test(Object receiver, String property, Object[] args, Object expectedValue) {

		if (receiver instanceof List) {
			List<?> list = (List<?>) receiver;
			if (list.size() == 1) {
				receiver = list.iterator().next();
			}
		}

		return receiver instanceof IPackageFragmentRoot;
	}
A {@link PropertyTester} used to determine if a given Eclipse resource is a Java package 
fragment root (which is basically a Java source folder on the build path).
GhidraBuild/EclipsePlugins/GhidraDev/GhidraDevPlugin/src/main/java/ghidradev/ghidraprojectcreator/testers/PackageFragmentRootPropertyTester.java