Github user azagrebin commented on a diff in the pull request:
https://github.com/apache/flink/pull/6228#discussion_r199806792
--- Diff:
flink-runtime/src/test/java/org/apache/flink/runtime/state/InternalPriorityQueueTestBase.java
---
@@ -0,0 +1,452 @@
+/*
+ * 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.state;
+
+import org.apache.flink.api.common.typeutils.CompatibilityResult;
+import org.apache.flink.api.common.typeutils.TypeSerializer;
+import org.apache.flink.api.common.typeutils.TypeSerializerConfigSnapshot;
+import org.apache.flink.core.memory.DataInputView;
+import org.apache.flink.core.memory.DataOutputView;
+import org.apache.flink.runtime.state.heap.HeapPriorityQueueElement;
+import org.apache.flink.util.CloseableIterator;
+import org.apache.flink.util.MathUtils;
+import org.apache.flink.util.TestLogger;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import javax.annotation.Nonnull;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * Testbase for implementations of {@link InternalPriorityQueue}.
+ */
+public abstract class InternalPriorityQueueTestBase extends TestLogger {
+
+ protected static final KeyGroupRange KEY_GROUP_RANGE = new
KeyGroupRange(0, 2);
+ protected static final KeyExtractorFunction<TestElement>
KEY_EXTRACTOR_FUNCTION = TestElement::getKey;
+ protected static final Comparator<TestElement> TEST_ELEMENT_COMPARATOR =
+
Comparator.comparingLong(TestElement::getPriority).thenComparingLong(TestElement::getKey);
+
+ protected static void insertRandomTimers(
--- End diff --
insertRandom**Elements**
---
