Github user tillrohrmann commented on a diff in the pull request:
https://github.com/apache/flink/pull/4757#discussion_r148606332
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/metrics/MetricsHeaders.java
---
@@ -0,0 +1,73 @@
+/*
+ * 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.rest.messages.metrics;
+
+import org.apache.flink.runtime.rest.HttpMethodWrapper;
+import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
+import org.apache.flink.runtime.rest.messages.MessageHeaders;
+
+import
org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
+
+/**
+ * Message header for metrics handler.
+ */
+public final class MetricsHeaders implements
MessageHeaders<EmptyRequestBody, MetricsOverview, MetricMessageParameters> {
+
+ private static final MetricsHeaders INSTANCE = new MetricsHeaders();
+
+ public static final String PARAMETER_JOB_ID = "jobid";
--- End diff --
where is this field used?
---
