docs: Collection<V> wrapValues(K key, Collection<V> values) {
  		final Object backEnd = DataViewDelegate.undelegate(values);
  		if (backEnd instanceof List<?>) {
  			return new SingleKeyValueListView(key, (List<V>) values);
  		}
  		if (backEnd instanceof Set<?>) {
  			return new SingleKeyValueSetView(key, (Set<V>) values);
  		}
  		throw new IllegalStateException("Unsupported type of the backend multimap: " + values.getClass()); //$NON-NLS-1$
  	}