Write by_surname(names) sorting full names by last word, then by full name.
by_surname(['Rahul Verma', 'Anita Sharma', 'Priya Nair']) → ['Priya Nair', 'Anita Sharma', 'Rahul Verma']
by_surname([]) → []
Submit runs 3 tests, including hidden edge cases.
Run your code to see the output here.