* @author Louis Wasserman
 */
@GwtIncompatible // unnecessary
@ElementTypesAreNonnullByDefault
class ImmutableMapEntry<K, V> extends ImmutableEntry<K, V> {
  /**
   * Creates an {@code ImmutableMapEntry} array to hold parameterized entries. The result must never
   * be upcast back to ImmutableMapEntry[] (or Object[], etc.), or allowed to escape the class.
   *