// // Licensed under the terms in License.txt // // Copyright 2010 Allen Ding. All rights reserved. // #import "KWNull.h" @implementation KWNull #pragma mark - Initializing + (id)null { static KWNull *sharedNull = nil; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ sharedNull = [self new]; }); return sharedNull; } @end