I have some NSDictionary like this:

```
@{
@"some key":{
    @"notImportantKey":@"asdasda",
    @"weight":@1
},
@"some key 2":{
    @"notImportantKey":@"asdasda",
    @"weight":@2
},
@"some key 3":{
    @"notImportantKey":@"asdasda",
    @"weight":@3
},
@"some key 4":{
    @"notImportantKey":@"asdasda",
    @"weight":@4
}}

```

I need array of keys (some key, some key2,...), sorted by weight value.