Update example of writing custom providers

docs/main/changelog.rst

@@ -16,6 +16,7 @@ Development version
 - Add ``Provider.last_overriding`` read-only property that points to last 
   overriding provider, if any. If target provider is not overridden, ``None``
   would be returned.
+- Update example of writing custom providers.
 
 3.4.3
 -----

docs/providers/custom.rst

@@ -12,9 +12,7 @@ Below are some tips and recommendations that have to be met:
     2. Cusom provider's ``__init__()`` could be overriden, but parent's
        initializer (:py:meth:`Provider.__init__`) has to be called.
     3. Providing strategy has to be implemented in custom provider's 
-       :py:meth:`Provider._provide` method. All ``*args`` & ``**kwargs`` 
-       that will be recieved by :py:meth:`Provider.__call__` will be 
-       transefed to custom provider's :py:meth:`Provider._provide`. 
+       :py:meth:`Provider.__call__` method.
     4. If custom provider is based on some standard providers, it is better to
        use delegation of standard providers, then extending of them.
     5. If custom provider defines any attributes, it is good to list them in 

examples/providers/custom_factory.py

@@ -17,17 +17,13 @@ class UsersFactory(providers.Provider):
         self._factory = providers.Factory(User)
         super(UsersFactory, self).__init__()
 
-    def _provide(self, *args, **kwargs):
-        """Return provided instance.
+    def __call__(self, *args, **kwargs):
+        """Return provided object.
 
-        :param args: tuple of context positional arguments
-        :type args: tuple[object]
-
-        :param kwargs: dictionary of context keyword arguments
-        :type kwargs: dict[str, object]
-
-        :rtype: object
+        Callable interface implementation.
         """
+        if self.last_overriding is not None:
+            return self.last_overriding._provide(args, kwargs)
         return self._factory(*args, **kwargs)