Please write code to change seconds_batches to be sorted_uniq_seconds in simplest way in Javascript
const seconds_batches = [
[1, 2, 3, 4],
[1, 2, 3, 4, 5, 6, 7],
[30, 31, 32, 33],
[1, 2, 3, 32, 33, 34, 35, 36, 37, 38, 39, 40],
]
const sorted_uniq_seconds = [1, 2, 3, 4, 5, 6, 7, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40]