Convert Java file to Kotlin -> Kotlin threw unc...

# random

[miha-x64]

Convert Java file to Kotlin -> Kotlin threw uncaught exception

static String pairsToString(Collection<IntPair> pairs) {
        StringBuilder builder = new StringBuilder(4 * pairs.size());
        for (Iterator<IntPair> iter = pairs.iterator(); iter.hasNext(); ) {
            IntPair pair = iter.next();
            builder.append(pair.getFirst()).append(' ').append(pair.getSecond());
            if (iter.hasNext()) {
                builder.append(',');
            }
        }
        return builder.toString();
    }