public FluentMatchingR<T, R> orElse(Function<T, R> function) {
    patterns.add(Pattern.of(t -> true, function::apply));
    return this;
  }
public FluentMatchingR < T , R > orElse ( Function < T , R > function ) { patterns . add ( Pattern . of ( t -> true , function :: apply ) ) ; return this ; }
Sets a {@link Function} to be run if no match is found.