         
         // Setup Label Mapping
         let labelMapping = RKObjectMapping(forClass: Label.self)
-        
-        let labelAttributeMap = [
+        labelMapping.addAttributeMappingsFromDictionary([
             "id":       "id",
             "name":     "name",
             "slug":     "slug",
             "icon":     "iconURL",
-        ]
-        
-        labelMapping.addAttributeMappingsFromDictionary(labelAttributeMap)
+            ]
+        )
         
         let labelResponseDescriptor = RKResponseDescriptor(
             mapping: labelMapping,

            "release":              "releaseDate",
            "track_count":          "trackCount",
            "collection":           "collectionID",
        ]
        
        mixtapeMap.addAttributeMappingsFromDictionary(mixtapeAttributeMap)
        
        let mixtapeList = RKResponseDescriptor(
            mapping: mixtapeMap,
            method: .GET,
            pathPattern: Path.Mixtape.List(),
            keyPath: "results",

        objectManager.addResponseDescriptor(trackList)
        
        let trackDetail = RKResponseDescriptor(
            mapping: trackMapping,
            method: .GET,
            pathPattern: Path.Track.Detail(),
            keyPath: nil,
