/**
* Returns an unmodifiable {@link CharArrayMap}. This allows to provide unmodifiable views of
* internal map for "read-only" use.
*
* @param map a map for which the unmodifiable map is returned.
* @return an new unmodifiable {@link CharArrayMap}.
* @throws NullPointerException if the given map is <code>null</code>.
*/
public static <V> CharArrayMap<V> unmodifiableMap(CharArrayMap<V> map) {
if (map == null) throw new NullPointerException("Given map is null");
if (map == emptyMap() || map.isEmpty()) return emptyMap();
if (map instanceof UnmodifiableCharArrayMap) return map;
return new UnmodifiableCharArrayMap<>(map);
}
