So, I stumbled across a method called "methodForSelector", which returns an IMP. Suppose I have two methods, A and B. B is supposed to cause the code in A's method definition to be fired after a delay, but needs to pass a double value as an argument; therefore B cannot call the method or A's performSelector method, and B also cannot use an NSInvocation. But if it can use an IMP, then what code do I need to put in to B?