public class SecurityContext
        {

            Dictionary<string, object> data;

            [JsonProperty("Username")]
            public string Username { get; private set; }

            [JsonProperty("Password")]
            public string Password { get; private set; }

            [JsonProperty("Data")]
            public Dictionary<string, object> Data
            {
                get { return data ?? (data = new Dictionary<string, object>()); }
                private set { data = value; }
            }

            [JsonConstructor]
            public SecurityContext(string username, string password)
            {
                Username = username;
                Password = password;
            }

            [JsonConstructor]
            public SecurityContext(string username, string password, Dictionary<string, object> data)
                : this(username, password)
            {
                Data = data;
            }
        }