public static <T> Indexed<T> index(long index, T value) {
        return new Indexed<>(index, value);
    }
public static < T > Indexed < T > index ( long index , T value ) { return new Indexed < > ( index , value ) ; }
Combine an index and a value into an indexed value.
@param index The index of the value.
@param value The value indexed.
@param <T> The type of the value.
@return The indexed value.