Android 4.1 xposed: prevent clearApplicationUserData for one package

import java.lang.reflect.Method;
 
import de.robv.android.xposed.IXposedHookLoadPackage;
import de.robv.android.xposed.XC_MethodHook;
import de.robv.android.xposed.XposedBridge;
import de.robv.android.xposed.XposedHelpers;
import de.robv.android.xposed.callbacks.XC_LoadPackage;
 
 
public class PreventClearApp implements IXposedHookLoadPackage
{
    @Override
    public void handleLoadPackage(XC_LoadPackage.LoadPackageParam lpparam)
    {
        XposedHelpers.findAndHookMethod(
            "com.android.server.pm.PackageManagerService",
            lpparam.classLoader,
            "clearApplicationUserData",
            String.class,
            "android.content.pm.IPackageDataObserver",
            int.class,
            new XC_MethodHook() {
                @Override
                protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
                    String packageName = (String) param.args[0];
                    XposedBridge.log("clearApplicationUserData: " + packageName);
                    if (packageName.equals("mypackage")) {
                        param.setResult(null);
 
                        //we do not have direct access to IPackageDataObserver, so we have to dance
                        Object observer = param.args[1];
                        if(observer != null) {
                            Class<?> iPackageDataObserverClass = Class.forName("android.content.pm.IPackageDataObserver");
                            Class<?>[] paramTypes = {String.class, boolean.class};
                            Method onRemoveCompletedMethod = iPackageDataObserverClass.getMethod("onRemoveCompleted", paramTypes);
                            Object[] params = {packageName, true};
                            try {
                                onRemoveCompletedMethod.invoke(observer, params);
                                //observer.onRemoveCompleted(packageName, true);
                            } catch (Exception e) {
                                XposedBridge.log("Observer no longer exists.");
                            }
                        }
                        //end dance
                    }
                }
            }
        );
    }
}