使用 Retrofit 解析动态密钥 Json 字符串

I'm trying to parse following dynamic key Json String.

"report":{
    "data":{
        "results":{
            "558952cca6d73d7d81c2eb9d":{
                "Max":-1,
                "Min":-1,
                "Slope":-1,
            },

            "558ce148a6d73d7d81c2fa8a":{
                "Max":-2,
                "Min":-1,
                "Slope":-2,
            }
        }
    }
}

Following I'm trying to get data, but getting error while parse last dynamic json String.

 public class Report {
        @SerializedName("data")
        @Expose
        private Data data;

        public Data getData() {
            return data;
        }

        public void setData(Data data) {
            this.data = data;
        }

        @Override
        public String toString() {
            return "Report{" +
                    "data=" + data +
                    '}';
        }
    }

    public class Data {
        @SerializedName("results")
        @Expose
        private ResultInside result;

        public ResultInside getResult() {
            return result;
        }

        public void setResult(ResultInside result) {
            this.result = result;
        }
    }

    public class ResultInside {
        /*@SerializedName("results")
        @Expose*/
        private Map<String, Vitals> elemDetails = new HashMap<>();

        public Map<String, Vitals> getElemDetails() {
            return elemDetails;
        }

        public void setElemDetails(Map<String, Vitals> elemDetails) {
            this.elemDetails = elemDetails;
        }
    }

Any suggestion how to parse in this case !