input: Write a python function to calculate the sum of a list of numbers.
  assert sum_list([1, 24, 47, 98, 22, 45]) == 237
  assert sum_list([0, 0, 0, 0]) == 0
  assert sum_list([-1, -24, -47, -98, -22, -45]) == -237
output: def sum_list(numbers):
      return sum(numbers)