* @param <V> namespace value type
* @param <N> namespace type
* @param <T> key type
- * @param <U> key type
+ * @param <U> value type
* @throws NamespaceNotAvailableException when the namespace is not available.
*/
public final <K, V, T extends K, U extends V, N extends IdentifierNamespace<K, V>> void addToNs(