Document proxy support in ReflectionTestUtils

Issue: SPR-14050

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

@@ -138,6 +138,9 @@ public class ReflectionTestUtils {
 	 * Set the {@linkplain Field field} with the given {@code name}/{@code type}
 	 * on the provided {@code targetObject}/{@code targetClass} to the supplied
 	 * {@code value}.
+	 * <p>If the supplied {@code targetObject} is a <em>proxy</em>, it will
+	 * be {@linkplain AopTestUtils#getUltimateTargetObject unwrapped} allowing
+	 * the field to be set on the ultimate target of the proxy.
 	 * <p>This method traverses the class hierarchy in search of the desired
 	 * field. In addition, an attempt will be made to make non-{@code public}
 	 * fields <em>accessible</em>, thus allowing one to set {@code protected},
@@ -154,6 +157,7 @@ public class ReflectionTestUtils {
 	 * @see ReflectionUtils#findField(Class, String, Class)
 	 * @see ReflectionUtils#makeAccessible(Field)
 	 * @see ReflectionUtils#setField(Field, Object, Object)
+	 * @see AopTestUtils#getUltimateTargetObject(Object)
 	 * @since 4.2
 	 */
 	public static void setField(Object targetObject, Class<?> targetClass, String name, Object value, Class<?> type) {
@@ -217,6 +221,9 @@ public class ReflectionTestUtils {
 	/**
 	 * Get the value of the {@linkplain Field field} with the given {@code name}
 	 * from the provided {@code targetObject}/{@code targetClass}.
+	 * <p>If the supplied {@code targetObject} is a <em>proxy</em>, it will
+	 * be {@linkplain AopTestUtils#getUltimateTargetObject unwrapped} allowing
+	 * the field to be retrieved from the ultimate target of the proxy.
 	 * <p>This method traverses the class hierarchy in search of the desired
 	 * field. In addition, an attempt will be made to make non-{@code public}
 	 * fields <em>accessible</em>, thus allowing one to get {@code protected},