Github user StefanRRichter commented on a diff in the pull request:
https://github.com/apache/flink/pull/6361#discussion_r203353112
--- Diff:
flink-end-to-end-tests/flink-stream-state-ttl-test/src/main/java/org/apache/flink/streaming/tests/verify/AbstractTtlStateVerifier.java
---
@@ -0,0 +1,132 @@
+/*
+ * 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.streaming.tests.verify;
+
+import org.apache.flink.api.common.state.State;
+import org.apache.flink.api.common.state.StateDescriptor;
+import org.apache.flink.api.common.state.StateTtlConfiguration;
+import org.apache.flink.api.common.time.Time;
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.runtime.state.FunctionInitializationContext;
+
+import javax.annotation.Nonnull;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+import java.util.stream.IntStream;
+
+abstract class AbstractTtlStateVerifier<D extends StateDescriptor<S, SV>,
S extends State, SV, UV, GV>
+ implements TtlStateVerifier<UV, GV> {
+ static final Random RANDOM = new Random();
+
+ @Nonnull
+ final D stateDesc;
+
+ AbstractTtlStateVerifier(@Nonnull D stateDesc) {
+ this.stateDesc = stateDesc;
+ }
+
+ @Nonnull
+ static String randomString() {
--- End diff --
You could use the existing `StringUtil.getRandomString(...)` instead of
your own random string generator.
---
