input: Write a python function to calculate the sum of a list of numbers.
  assert get_sum([1, 2, 3, 4, 5]) == 15
  assert get_sum([10, -2, 3, 7, 0]) == 18
  assert get_sum([5, 5, 5, 5, 5]) == 25
output: def get_sum(numbers):
      return sum(numbers)