delim +++

String calculator

@@ -125,6 +125,8 @@ class TestStingCalculator(unittest.TestCase):
         self.assertEqual(str(e.exception),"negatives not allowed: -3")
     def test_custom_delimiter(self):
         self.assertEqual(self.calculator.add("//[***]\n1***2***3"),6)
+    def test_custom_del(self):
+        self.assertEqual(self.calculator.add("//[+++]\n1+++2+++3"),6)