fix logger

Author: injectives

driver/src/main/java/org/neo4j/driver/internal/bolt/basicimpl/BoltConnectionImpl.java

@@ -73,6 +73,7 @@
 
 public final class BoltConnectionImpl implements BoltConnection {
     private final LoggingProvider logging;
+    private final System.Logger log;
     private final BoltProtocol protocol;
     private final Connection connection;
     private final EventLoop eventLoop;
@@ -110,6 +111,7 @@ public BoltConnectionImpl(
         this.messageWriters = new ArrayDeque<>();
         this.clock = Objects.requireNonNull(clock);
         this.logging = Objects.requireNonNull(logging);
+        this.log = this.logging.getLog(getClass());
     }
 
     @Override
@@ -422,6 +424,7 @@ public CompletionStage<Void> flush(ResponseHandler handler) {
                                 }
                             } else {
                                 flushFuture.complete(null);
+                                log.log(System.Logger.Level.DEBUG, "flushed");
                             }
                         });
                     } else {