The ``current_language`` manager method is a deprecated alias for the last form.
+Retrieving a single translation object
+The custom manager object has a shortcut for retrieving a single translation
+object, which may be very useful when used on related source objects. The method
+is named ``get_by_lang()`` and is called with an optional language code. The
+language code defaults to the currently active language. Here's an example::
+ my_source.translations.get_by_lang() # Retrieves 'de' translation
+ my_source.translations.get_by_lang('es') # Retrieves 'es' translation
+The added benefit of using this shortcut is that it reuses the existing
+queryset, so it works well with methods like ``prefetch_related``.