src/main/java/com/googlecode/objectify/util/IdentityMultimapList.java
public boolean add(K key, V value) {

		List<V> list = this.get(key);
		if (list == null) {
			list = new ArrayList<>();
			this.put(key, list);
		}

		return list.add(value);
	}
public boolean add(K key, V value) {

		List<V> list = this.get(key);
		if (list == null) {
			list = new ArrayList<>();
			this.put(key, list);
		}

		return list.add(value);
	}
public boolean add ( K key , V value ) { List < V > list = this . get ( key ) ; if ( list == null ) { list = new ArrayList <> ( ) ; this . put ( key , list ) ; } return list . add ( value ) ; }
Adds a value to the set associated with the key.
Adds a value to the set associated with the key .