Revert "Change __init__(self) to __new__(cls)"

This reverts commit 9ed8b44033e64f2990bf123b5057e92b8142edae.
diff --git a/docs/advanced/cast/custom.rst b/docs/advanced/cast/custom.rst
index f803594..e4f99ac 100644
--- a/docs/advanced/cast/custom.rst
+++ b/docs/advanced/cast/custom.rst
@@ -23,7 +23,7 @@
 .. code-block:: python
 
     class A:
-        def __new__(cls):
+        def __int__(self):
             return 123
 
     from example import print