construct
method.Serializer::setGroups, Serializer::setExclusionStrategy and Serializer::setVersion were removed, these settings must now be passed as part of a new Context object.
Before:
$serializer->setVersion(1);
$serializer->serialize($data, 'json');
After:
$serializer->serialize($data, 'json', SerializationContext::create()->setVersion(1));
All visit??? methods of the VisitorInterface, now require a third argument, the Context; the context is for example passed as an additional argument to handlers, exclusion strategies, and also available in event listeners.