minor refactor: remove gradle warning about no tests

subprojects/performance/src/test/groovy/DummyTest.groovy

@@ -0,0 +1,31 @@
+/*
+ *  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.
+ */
+
+import org.junit.Test
+
+/**
+ * Gradle complains if we have no tests, so this keeps it happy
+ */
+final class DummyTest {
+
+    @Test
+    void testTrue() {
+        assert 1 + 1 == 2
+    }
+}