Random Java exercise: How do you concatenate a List of Iterables taking all of the first elements, then all of the second elements, etc.? For example, if you have:
[[a, b, c, d],
[e, f, g, h],
[i, j, k]]
where the outer brackets represent a List, and the inner brackets are Iterables, how do you get this to return:
[a, e, i, b, f, j, c, g, k, d, h]