input: Write a function to design a data structure in Python that stores integer values and supports the operations of adding values and finding the minimum value. The function should return the designed class.
  class IntList:
      def __init__(self):
          self.values = []
      
      def add_value(self, value):
          self.values.append(value)
      
      def find_min(self):
          return min(self.values)
  
  assert isinstance(IntList(), IntList) == True
  int_list_instance = IntList()
  int_list_instance.add_value(5)
  int_list_instance.add_value(3)
  int_list_instance.add_value(8)
  assert int_list_instance.find_min() == 3
output: class IntList:
      def __init__(self):
          self.values = []
      
      def add_value(self, value):
          self.values.append(value)
      
      def find_min(self):
          return min(self.values)