input: Write a python function to perform basic arithmetic operations using a class.
  assert Arithmetic(2, 4).addition() == 6
  assert Arithmetic(2, 4).subtraction() == -2
  assert Arithmetic(2, 4).multiplication() == 8
  assert Arithmetic(2, 4).division() == 0.5
  assert Arithmetic(10, 5).addition() == 15
  assert Arithmetic(10, 5).subtraction() == 5
  assert Arithmetic(10, 5).multiplication() == 50
  assert Arithmetic(10, 5).division() == 2.0
output: class Arithmetic:
      def __init__(self, a, b):
          self.a = a
          self.b = b
  
      def addition(self):
          return self.a + self.b
  
      def subtraction(self):
          return self.a - self.b
  
      def multiplication(self):
          return self.a * self.b
  
      def division(self):
          return self.a / self.b