#Insert_at(pos) inserts at wrong position when moving down

[javinto]

If find this an unexpected result from the #insert_at(pos) method:

Suppose you have:
1 A
2 B
3 C
4 D
5 E
6 F
7 G

And you move E to position 3 (before C) by #insert_at(3) the result will be as expected:
1 A
2 B
3 E
4 C
5 D
6 F
7 G

But now - starting all over - you move C to position 6 (before F), the result will be unexpected:
1 A
2 B
3 D
4 E
5 F
6 C
7 G

Technically, yes C has arrived on position 6, but NOT before 'F' as meant to be from a sorting point of view.

I consider this an issue. One way to solve it, is by adding a new method #move_to(pos) ?