private void SaveToJson(string fileName, ArmSquenceList list)
    {
        var jsonPath = Application.persistentDataPath + "/" + fileName;
        var str      = JsonUtility.ToJson(list);

        System.IO.File.WriteAllText(jsonPath, str);
    }
    private ArmSquenceList GetSequenceFromPath(string fileName)
    {
        var            jsonPath = Application.persistentDataPath + "/" + fileName;
        ArmSquenceList list     = null;

        if (System.IO.File.Exists(jsonPath))
        {
            var str = System.IO.File.ReadAllText(jsonPath);
            list = JsonUtility.FromJson <ArmSquenceList>(str);
        }

        if (list == null)
        {
            list = new ArmSquenceList();
        }
        return(list);
    }