1 files changed, 19 insertions, 0 deletions
diff --git a/docs/examples/userguide/language_basics/optional_subclassing.py b/docs/examples/userguide/language_basics/optional_subclassing.py
new file mode 100644
index 000000000..480ae100b
--- /dev/null
+++ b/docs/examples/userguide/language_basics/optional_subclassing.py
@@ -0,0 +1,19 @@
+from __future__ import print_function
+
+@cython.cclass
+class A:
+    @cython.cfunc
+    def foo(self):
+        print("A")
+
+@cython.cclass
+class B(A):
+    @cython.cfunc
+    def foo(self, x=None):
+        print("B", x)
+
+@cython.cclass
+class C(B):
+    @cython.ccall
+    def foo(self, x=True, k:cython.int = 3):
+        print("C", x, k)