src/main/java/com/googlecode/objectify/impl/translate/LoadContext.java
public <T> Ref<T> loadRef(Key<T> key, LoadConditions loadConditions) {
		return engine.makeRef(currentRoot, loadConditions, key);
	}
public <T> Ref<T> loadRef(Key<T> key, LoadConditions loadConditions) {
		return engine.makeRef(currentRoot, loadConditions, key);
	}
Create a Ref for the key, and maybe start a load operation depending on current load groups.