public JavaClass lookupClass(@NonNull String className) throws ClassNotFoundException {  if (className == null) throw new IllegalArgumentException("className is null"); return Repository.lookupClass(className);  }
public abstract JavaClass lookupClass(@NonNull String className) throws ClassNotFoundException;
	public JavaClass lookupClass(@NonNull String className) throws ClassNotFoundException {		// TODO: eventually we should move to our own thread-safe repository implementation		if (className == null) throw new IllegalArgumentException("className is null");		return Repository.lookupClass(className);		// note: previous line does not throw ClassNotFoundException, instead returns null	}