Test a Sorted List Merge

merge(a, b) takes two lists of numbers, each sorted from smallest to largest, and returns a new sorted list holding every item from both, duplicates included. It must not change a or b.

Write test_ functions with assert that pass on a correct version and fail on broken ones.

Examples

merge([1, 4], [2, 3])    # [1, 2, 3, 4]
merge([5], [])           # [5]