private static MethodHandles.Lookup lookupIn(final Class<?> declaringClass) {

        try {
            final Constructor<MethodHandles.Lookup> constructor = MethodHandles.Lookup.class.getDeclaredConstructor(
                    Class.class,
                    int.class);
            constructor.setAccessible(true);
            return constructor.newInstance(declaringClass, MethodHandles.Lookup.PRIVATE);
        } catch (NoSuchMethodException | InvocationTargetException | InstantiationException | IllegalAccessException e) {
            throw new RuntimeException(e);
        }

    }
private static MethodHandles . Lookup lookupIn ( final Class < ? > declaringClass ) { try { final Constructor < MethodHandles . Lookup > constructor = MethodHandles . Lookup . class . getDeclaredConstructor ( Class . class , int . class ) ; constructor . setAccessible ( true ) ; return constructor . newInstance ( declaringClass , MethodHandles . Lookup . PRIVATE ) ; } catch ( NoSuchMethodException | InvocationTargetException | InstantiationException | IllegalAccessException e ) { throw new RuntimeException ( e ) ; } }
Creates a method lookup that is capable of accessing private members of declaring classes this Mixin factory has
usually no access to.

@param declaringClass
@return
@throws NoSuchMethodException
@throws IllegalAccessException
@throws InvocationTargetException
@throws InstantiationException