code: public static <T extends Case2<A, B>, A, B, EB extends B> DecomposableMatchBuilder0<T> case2(
        Class<T> clazz, MatchesExact<A> a, DecomposableMatchBuilder0<EB> b) {
      List<Matcher<Object>> matchers = Lists.of(ArgumentMatchers.eq(a.t), ArgumentMatchers.any());
      return new DecomposableMatchBuilder1<T, EB>(matchers, 1, new Case2FieldExtractor<>(clazz))
          .decomposeFirst(b);
    }
docs: Matches a case class of two elements.
  
  <p>If matched, the {@code b} value is decomposed to 0.