Missing abstract declaration on ReflectionTestUtils

Issue: SPR-15757

Author: jhoeller

spring-test/src/main/java/org/springframework/test/util/ReflectionTestUtils.java

@@ -64,7 +64,7 @@
  * @see ReflectionUtils
  * @see AopTestUtils
  */
-public class ReflectionTestUtils {
+public abstract class ReflectionTestUtils {
 
 	private static final String SETTER_PREFIX = "set";