public static void FLMutableDict_SetString(FLMutableDict x, string key, string str)
 {
     using (var key_ = new C4String(key))
         using (var str_ = new C4String(str)) {
             NativeRaw.FLMutableDict_SetString(x, (FLSlice)key_.AsFLSlice(), (FLSlice)str_.AsFLSlice());
         }
 }