code: public final <C> Converter<A, C> andThen(Converter<B, C> secondConverter) {
      return doAndThen(secondConverter);
    }
docs: Returns a converter whose {@code convert} method applies {@code secondConverter} to the result
  of this converter. Its {@code reverse} method applies the converters in reverse order.
  
  <p>The returned converter is serializable if {@code this} converter and {@code secondConverter}
  are.