Merge branch '7.1' into 7.2

* 7.1:
  Update messenger.rst

messenger.rst

@@ -2587,7 +2587,7 @@ provided in order to ease the declaration of these special handlers::
         // of the trait to define your own batch size...
         private function shouldFlush(): bool
         {
-            return 100 <= \count($this->jobs);
+            return $this->getBatchSize() <= \count($this->jobs);
         }
 
         // ... or redefine the `getBatchSize()` method if the default