FixDictionaryCategory

NSString *string = nil;
NSDictionary *dic = @{
                      string:@"first key",
                      @"testkey":@"testObject",
                      @"last object":string
                      };
NSLog(@"dic is %@",dic);

---

2016-08-29 16:20:40.188 FixDictionary[16620:537697] CharlotteTip : key is nil(object is “first key”)
2016-08-29 16:20:40.189 FixDictionary[16620:537697] CharlotteTip : object is nil(key is “last object”)
2016-08-29 16:20:40.189 FixDictionary[16620:537697] fixd dictionary is {
    testkey = testObject;
}
2016-08-29 16:20:40.189 FixDictionary[16620:537697] dic is {
    testkey = testObject;
}