--- old/src/java.base/share/classes/java/lang/Class.java	2015-01-10 13:43:09.635162120 +0100
+++ new/src/java.base/share/classes/java/lang/Class.java	2015-01-10 13:43:09.536164093 +0100
@@ -69,6 +69,8 @@
 import sun.security.util.SecurityConstants;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Proxy;
+import java.util.function.Function;
+
 import sun.reflect.annotation.*;
 import sun.reflect.misc.ReflectUtil;
 
@@ -2562,6 +2564,27 @@
         return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
     }
 
+    /**
+     * If this Class represents a generic class or interface, then the result of
+     * applying given function to this Class object is returned, otherwise null.
+     * The result is cached in per-Class map using identity of given key.
+     * In case of races, the function may be invoked multiple times for the same
+     * key, therefore it should be idempotent.
+     *
+     * @param key the non-null key who's identity is used for caching of the result
+     * @param function the function applied to this Class to compute the result
+     * @param <D> the type of result
+     * @return the cached result of applying given function to this Class or null
+     * @throws java.lang.NullPointerException if given key or function is null
+     */
+    <D> D getGenericDerivative(Object key, Function<Class<?>, ? extends D> function) {
+        if (key == null || function == null) throw new NullPointerException();
+        ClassRepository genericInfo = getGenericInfo();
+        return (genericInfo == null)
+            ? null
+            : genericInfo.getDerivative(this, key, function);
+    }
+
     // Annotations handling
     native byte[] getRawAnnotations();
     // Since 1.8