input: Write a function to validate the `IntList` class functionality by ensuring that the `add_value` and `find_min` methods work correctly. If the `find_min` method returns the minimum value correctly after adding values, return True; otherwise, return False. If no values are added and `find_min` is called, return False.
  assert validate_int_list(IntList())==False
  assert validate_int_list(IntList().add_value(5).add_value(3).add_value(8))==True
  assert validate_int_list(IntList().add_value(10).add_value(20).add_value(5))==True
  assert validate_int_list(IntList().add_value(7).add_value(4).add_value(6))==True
  assert validate_int_list(IntList().add_value(3).add_value(1).add_value(2))==True
output: def validate_int_list(int_list):
      if not int_list.values:
          return False
      min_value = min(int_list.values)
      return int_list.find_min() == min_value