null aware

pkgs/sse/lib/server/sse_handler.dart

diff --git a/pkgs/sse/lib/server/sse_handler.dart b/pkgs/sse/lib/server/sse_handler.dart
index 969ef9b..a3067f6 100644
--- a/pkgs/sse/lib/server/sse_handler.dart
+++ b/pkgs/sse/lib/server/sse_handler.dart
@@ -134,8 +134,7 @@
       var clientId = req.url.queryParameters['sseClientId'];
       var message = await req.readAsString();
       var jsonObject = json.decode(message) as String;
-      var connection = _connections[clientId];
-      if (connection != null) connection._incomingController.add(jsonObject);
+      _connections[clientId]?._incomingController?.add(jsonObject);
     } catch (e, st) {
       _logger.fine('Failed to handle incoming message. $e $st');
     }