diff --git a/Feature2.py b/Feature2.py
new file mode 100644
index 0000000000000000000000000000000000000000..313c83859224784eac53ffb5958c3e0c872ee112
--- /dev/null
+++ b/Feature2.py
@@ -0,0 +1,41 @@
+from abc import ABC, abstractmethod
+import unittest
+
+class IStringCalculator(ABC):
+    @abstractmethod
+    def add(self, numbers: str) -> int:
+        pass
+
+class StringCalculator(IStringCalculator):
+    def add(self, numbers: str) -> int:
+        if not numbers:
+            return 0
+        # Ersetze Zeilenumbrüche durch Kommas und teile die Eingabe nach Kommas
+        numbers = numbers.replace("\n", ",")
+        return sum(map(int, numbers.split(',')))
+
+class TestStringCalculator(unittest.TestCase):
+    def setUp(self):
+        self.calculator = StringCalculator()
+    
+    def test_empty_string(self):
+        self.assertEqual(self.calculator.add(""), 0)
+    
+    def test_single_number(self):
+        self.assertEqual(self.calculator.add("1"), 1)
+    
+    def test_two_numbers(self):
+        self.assertEqual(self.calculator.add("1,2"), 3)
+    
+    def test_multiple_numbers(self):
+        self.assertEqual(self.calculator.add("1,2,3,4,5"), 15)
+    
+    def test_numbers_with_newline(self):
+        self.assertEqual(self.calculator.add("1\n2,3"), 6)
+    
+    def test_numbers_with_multiple_newlines(self):
+        self.assertEqual(self.calculator.add("1\n2\n3\n4\n5"), 15)
+
+if __name__ == "__main__":
+    unittest.main()
+