code: private static <K, V> Map.Entry<K, V> createEntry(K key, V value) {
  		return new Map.Entry<K, V>() {
  			@Override
  			public K getKey() {
  				return key;
  			}
  
  			@Override
  			public V getValue() {
  				return value;
  			}
  
  			@Override
  			public V setValue(V value) {
  				throw new UnsupportedOperationException();
  			}
  		};
  	}
docs: Creates an immutable Map.Entry.