input: Write a function to take a list of numbers from 1 to 8 and return a new list containing the cubic values of each number in the original list.
  assert cube_list([1, 2, 3, 4, 5, 6, 7, 8])==[1, 8, 27, 64, 125, 216, 343, 512]
  assert cube_list([])==[]
  assert cube_list([1, 2, 3])==[1, 8, 27]
output: def cube_list(numbers):
      return [x**3 for x in numbers]