default T20 getOrNull20() {
        return get20().orElse(null);
    }
Returns the 20th element from this tuple or {@code null} if no such
element is present.

@return the 20th element from this tuple or {@code null} if no such
        element is present.
common-parent/tuple/src/main/java/com/speedment/common/tuple/nullable/Tuple21OfNullables.java