Add Lang1703Test

src/test/java/org/apache/commons/lang3/reflect/Lang1703Test.java

@@ -0,0 +1,35 @@
+/*
+ * 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.commons.lang3.reflect;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * A top-level class is parameterised using itself.
+ *
+ * @param <U> itself
+ */
+public class Lang1703Test<U extends Lang1703Test<U>> {
+
+    @Test
+    public void testStackOverflowError() {
+        // causes a java.lang.StackOverflowError
+        TypeUtils.toString(Lang1703Test.class);
+    }
+
+}