http://www.cocoachina.com/ios/20160505/16112.html
http://cocoadocs.org/docsets/BlocksKit/2.2.5/Categories/NSObject+A2BlockDelegate.html
http://www.jeepshoe.org/249144506.htm
https://github.com/zwaldowski/BlocksKit
http://www.cocoachina.com/ios/20160505/16112.html
http://cocoadocs.org/docsets/BlocksKit/2.2.5/Categories/NSObject+A2BlockDelegate.html
http://www.jeepshoe.org/249144506.htm
https://github.com/zwaldowski/BlocksKit