Latest ISO datetime
In this task, you need to return the later datetime string between the given two.
Input: Two strings.
Output: String.
Examples:
assert get_latest("2007-03-04T21:08:12", "2007-03-04T21:08:12") == "2007-03-04T21:08:12"
assert get_latest("2027-09-01T01:03:10", "1997-04-15T11:18:14") == "2027-09-01T01:03:10"
assert get_latest("0001-01-01T01:01:01", "3000-11-16T13:27:02") == "3000-11-16T13:27:02"
How it’s used: For sequential data arrangement, when working with time series.
Preconditions: Datetime arguments >= 0001-01-01T01:01:01.
