Merge branch '5.2' into 5.3

* 5.2:
  [Migration guide] Change Strangler App to Strangler Fig App
  [HttpClient] Import ServerSentEvent class

Author: javiereguiluz

http_client.rst

@@ -1270,7 +1270,8 @@ Symfony's HTTP client provides an EventSource implementation to consume these
 server-sent events. Use the :class:`Symfony\\Component\\HttpClient\\EventSourceHttpClient`
 to wrap your HTTP client, open a connection to a server that responds with a
 ``text/event-stream`` content type and consume the stream as follows::
-
+    
+    use Symfony\Component\HttpClient\Chunk\ServerSentEvent;
     use Symfony\Component\HttpClient\EventSourceHttpClient;
 
     // the second optional argument is the reconnection time in seconds (default = 10)

migration.rst

@@ -7,7 +7,7 @@ Migrating an Existing Application to Symfony
 When you have an existing application that was not built with Symfony,
 you might want to move over parts of that application without rewriting
 the existing logic completely. For those cases there is a pattern called
-`Strangler Application`_. The basic idea of this pattern is to create a
+`Strangler Fig Application`_. The basic idea of this pattern is to create a
 new application that gradually takes over functionality from an existing
 application. This migration approach can be implemented with Symfony in
 various ways and has some benefits over a rewrite such as being able
@@ -464,7 +464,7 @@ chance to use Symfony's event lifecycle. For instance, this allows you to
 transition the authentication and authorization of the legacy application over
 to the Symfony application using the Security component and its firewalls.
 
-.. _`Strangler Application`: https://martinfowler.com/bliki/StranglerFigApplication.html
+.. _`Strangler Fig Application`: https://martinfowler.com/bliki/StranglerFigApplication.html
 .. _`autoload`: https://getcomposer.org/doc/04-schema.md#autoload
 .. _`Modernizing with Symfony`: https://youtu.be/YzyiZNY9htQ
 .. _`Symfony Panther`: https://github.com/symfony/panther