diff --git a/tests/test_class_demo.py b/tests/test_class_demo.py
new file mode 100644
index 0000000..f2e42b9
--- /dev/null
+++ b/tests/test_class_demo.py
@@ -0,0 +1,9 @@
+class TestClassDemoInstance:
+    value = 0
+
+    def test_one(self):
+        self.value = 1
+        assert self.value == 1
+
+    def test_two(self):
+        assert self.value == 1
\ No newline at end of file