Replaced 'return' by 'raise' in custom model field docs
Thanks Simon Charette for noticing it. Refs #11162.
|@@ -440,7 +440,7 @@ database, so we need to be able to process strings and ``Hand`` instances in|
|Notice that we always return a ``Hand`` instance from this method. That's the|
|Python object type we want to store in the model's attribute. If anything is|
|-going wrong during value conversion, you should return a|
|+going wrong during value conversion, you should raise a|
|**Remember:** If your custom field needs the :meth:`to_python` method to be|