def test_3_should_be_minus(self):
		operator = Operator(3)
		self.assertEqual('-', operator.to_string())
	def test_1_should_be_plus(self):
		operator = Operator(1)
		self.assertEqual('+', operator.to_string())
	def test_2_should_be_multiply(self):
		operator = Operator(2)
		self.assertEqual('*', operator.to_string())
	def operator(self):
		operator = Operator(self.operand)
		return  operator.to_string()