@@ -152,12 +152,14 @@ needs three parameters:
152152#. The name of the class this information will be decoded to
153153#. The encoder used to convert that information into an array
154154
155- By default, additional attributes that are not mapped to the denormalized object will be ignored
156- by the Serializer component. Set the ``allow_extra_attributes `` keyof thedeserialization contextto `` false ``
157- to let the serializer throw an exception when additional attributes are passed .
155+ .. versionadded :: 3.3
156+ Support for the ``allow_extra_attributes `` keyin the contextwas introduced
157+ in Symfony 3.3 .
158158
159- This will throw an:class: `Symfony\\ Component\\ Serializer\\ Exception\\ ExtraAttributesException ` exception,
160- because city is not an attribute of the ``Person `` class::
159+ By default, additional attributes that are not mapped to the denormalized
160+ object will be ignored by the Serializer component. Set the ``allow_extra_attributes ``
161+ key of the deserialization context to ``false `` to let the serializer throw
162+ an exception when additional attributes are passed::
161163
162164 $data = <<<EOF
163165 <person>
@@ -167,6 +169,8 @@ because city is not an attribute of the ``Person`` class::
167169 </person>
168170 EOF;
169171
172+ // this will throw a Symfony\Component\Serializer\Exception\ExtraAttributesException
173+ // because "city" is not an attribute of the Person class
170174 $person = $serializer->deserialize($data, 'Acme\Person', 'xml', array(
171175 'allow_extra_attributes' => false,
172176 ));