input: Write a python function to calculate the sum of a list of numbers.
  assert calculate_sum([1, 2, 3, 4, 5]) == 15
  assert calculate_sum([10, 20, 30, 40, 50]) == 150
  assert calculate_sum([5, 7, 9, 11, 13]) == 45
output: def calculate_sum(numbers):
      return sum(numbers)