objective-c : steps for setting up the delegate pattern between two objects

snippet.m

//steps for setting up the delegate pattern between two objects

//steps for setting up the delegate pattern between two objects, 
//where object A is the delegate for object B and object B will send out the messages:
//1. Define a delegate @protocol for object B.
//2. Give object B a property for that delegate protocol.
//3. Make object B send messages to its delegate when something interesting happens, 
//such as the user pressing the Cancel or Done buttons, or when it needs a piece of information.
//4. Make object A conform to the delegate protocol. 
//It should put the name of the protocol in its @interface line and implement the methods from the protocol.
//5. Tell object B that object A is now its delegate.
//This means there is one more thing you need to do: 
//tell AddItemViewController that the ChecklistsViewController is now its delegate. 
//The proper place to do that when you’re using storyboards is in the prepareForSegue:sender: method.