}
}

public fun <A : Any> List<A>.mergeInto(destination: MutableList<A>, f: SublistMerger<A>.() -> Unit) {
    SublistMerger(this, destination).apply {
        f()
        finish()
    }
}

public fun <A : Any> List<A>.mergeWith(f: SublistMerger<A>.() -> Unit): List<A> =
    mutableListOf<A>().also { destination -> mergeInto(destination, f) }

func (i1 Interval) adjacent(i2 Interval) bool {
	return i1.en == i2.st || i2.en == i1.st
}

// MergeInto merges interval i2 into i1. This version happens to
// require that the two intervals either overlap or are adjacent.
func (i1 *Interval) MergeInto(i2 Interval) error {
	if !i1.Overlaps(i2) && !i1.adjacent(i2) {
		return fmt.Errorf("merge method invoked on non-overlapping/non-adjacent")
	}