public void Dispose()
 {
     if (accountClient != null)
     {
         accountClient.Dispose();
         accountClient = null;
     }
 }
        public BetfairAccount Login(string sessionToken)
        {
            this.sessionToken = sessionToken;

            this.accountClient = new BetfairAccountClient(applicationId, sessionToken);

            return GetBetfairAccount();
        }