Method unmodifiableEntry

guava/src/com/google/common/collect/Maps.java:1479–1495

Returns an unmodifiable view of the specified map entry. The {@link Entry#setValue} operation throws an {@link UnsupportedOperationException}. This also has the side effect of redefining {@code equals} to comply with the Entry contract, to avoid a possible nefarious implementation of equals. @param

(
      Entry<? extends K, ? extends V> entry)

   * @return an unmodifiable view of the entry
   */
  static <K extends @Nullable Object, V extends @Nullable Object> Entry<K, V> unmodifiableEntry(
      Entry<? extends K, ? extends V> entry) {
    checkNotNull(entry);
    return new AbstractMapEntry<K, V>() {
      @Override
      @ParametricNullness
      public K getKey() {
        return entry.getKey();
      }

      @Override
      @ParametricNullness
      public V getValue() {
        return entry.getValue();
      }
    };
  }

  static <K extends @Nullable Object, V extends @Nullable Object>
      UnmodifiableIterator<Entry<K, V>> unmodifiableEntryIterator(