input: Write a function that converts a given string into a list of integers. The string is expected to contain integers separated by commas. If the string is empty, the function should return an empty list.
  
  def to_int_list(s):
      return [int(x) for x in s.split(',')]
  
  assert to_int_list("1,2,3,4,5")==[1, 2, 3, 4, 5]
  assert to_int_list("10,20,30,40,50")==[10, 20, 30, 40, 50]
  assert to_int_list("1,1,1,1,1,1,1")==[1, 1, 1, 1, 1, 1, 1]
  assert to_int_list("")==[]
output: def to_int_list(s):
      if s == "":
          return []
      return [int(x) for x in s.split(',')]