Github user tillrohrmann commented on a diff in the pull request:
https://github.com/apache/flink/pull/4802#discussion_r144005365
--- Diff:
flink-clients/src/test/java/org/apache/flink/client/CliFrontendListTest.java ---
@@ -0,0 +1,72 @@
+/*
+ * 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.client;
+
+import org.apache.flink.client.util.MockedCliFrontend;
+import org.apache.flink.util.TestLogger;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.mockito.Mockito;
+
+import java.util.Collections;
+import java.util.concurrent.CompletableFuture;
+
+import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.times;
+import static org.powermock.api.mockito.PowerMockito.when;
+
+/**
+ * Tests for the CANCEL command.
--- End diff --
typo: LIST command.
---
