Test a Number Sorting Function

Problem

Given a function sort_numbers(nums) that takes a list of integers and returns the list sorted in non-decreasing order, write a Python test helper that verifies whether the function behaves correctly. The helper should return True only if all required test cases pass, and False otherwise.

Constraints

• 0 <= len(nums) <= 10^4 for any individual test case
• List values may be negative, zero, or positive integers
• The test helper must check multiple cases, including empty input, one element, duplicates, and negative numbers