input: Write a function that converts a given string to a list of integers. The input string is assumed to be a comma-separated list of integers. The function should return a list of these integers.
  
  def to_int_list(s):
      return [int(x) for x in s.split(',')]
  
  assert to_int_list("1,2,3,4")==[1, 2, 3, 4]
  assert to_int_list("5,6,7,8,9")==[5, 6, 7, 8, 9]
  assert to_int_list("10,20,30,40,50")==[10, 20, 30, 40, 50]
  assert to_int_list("100,200,300")==[100, 200, 300]
  assert to_int_list("")==[]
output: def to_int_list(s):
      return [int(x) for x in s.split(',')]