input: Write a python function to calculate the product of all numbers in a list.
  assert multiply_list([1, 2, 3, 4]) == 24
  assert multiply_list([5, 5, 5, 5]) == 625
  assert multiply_list([2, 3, 7]) == 42
output: def multiply_list(numbers):
      product = 1
      for number in numbers:
          product *= number
      return product