docs: public static <T> Map<T, T> reverse(Map<T, T> map) {
  		return filter(map, new Editor<Map.Entry<T, T>>() {
  			@Override
  			public Entry<T, T> edit(final Entry<T, T> t) {
  				return new Entry<T, T>() {
  
  					@Override
  					public T getKey() {
  						return t.getValue();
  					}
  
  					@Override
  					public T getValue() {
  						return t.getKey();
  					}
  
  					@Override
  					public T setValue(T value) {
  						throw new UnsupportedOperationException("Unsupported setValue method !");
  					}
  				};
  			}
  		});
  	}