docs: @Override
      public <H> Choice7<A, B, C, D, E, F, H> flatMap(
              Function<? super G, ? extends Monad<H, Choice7<A, B, C, D, E, F, ?>>> fn) {
          return match(Choice7::a, Choice7::b, Choice7::c, Choice7::d, Choice7::e, Choice7::f, g -> fn.apply(g).coerce());
      }