// Initialize from the source (the method call will be invoked on this object)
STXScrollDelegateProxy *proxy = [[STXScrollDelegateProxy alloc] initWithSource:self];

// If you have any selectors that you'd like to intercept, set the interceptor
proxy.interceptor = self.interceptor;

// If you have any broadcasting selectors, you can consider adding some subscribers to be notified
[proxy addBroadcastSubscriber:subscriber];

// Define the proxying policy for selector
[proxy setProxyingSelector:@selector(scrollViewWillBeginDragging:)
            withRunningMode:mode];