Github user GJL commented on a diff in the pull request:
https://github.com/apache/flink/pull/5451#discussion_r169682725
--- Diff:
flink-runtime/src/test/java/org/apache/flink/runtime/webmonitor/retriever/TestingGatewayRetriever.java
---
@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.runtime.webmonitor.retriever;
+
+import org.apache.flink.runtime.rpc.RpcGateway;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Testing {@link GatewayRetriever} implementation which can be
+ * manually set.
+ *
+ * @param <T> type of the gateway
+ */
+public class TestingGatewayRetriever<T extends RpcGateway> implements
GatewayRetriever<T> {
+ private CompletableFuture<T> gatewayFuture;
+
+ public TestingGatewayRetriever() {
+ gatewayFuture = new CompletableFuture<>();
+ }
+
+ @Override
+ public CompletableFuture<T> getFuture() {
+ return null;
--- End diff --
I think there is a better value than `null` to return.
---
