docs: public Choice<T> or(final Choice<T> other) {
      checkNotNull(other);
      if (other == none()) {
        return this;
      } else {
        final Choice<T> thisChoice = this;
        return new Choice<T>() {
          @Override
          protected Iterator<T> iterator() {
            return Iterators.concat(thisChoice.iterator(), other.iterator());
          }
  
          @Override
          public String toString() {
            return String.format("%s.or(%s)", thisChoice, other);
          }
        };
      }
    }