public static AccessTokenStore Instance()
        {
            if (_instance == null)
            {
                _instance = new AccessTokenStore();
            }

            return(_instance);
        }
 private OfficeDocumentStore()
 {
     _identityServerUmaClientFactory = new IdentityServerUmaClientFactory();
     _identityServerClientFactory    = new IdentityServerClientFactory();
     _documentManagementFactory      = new DocumentManagementFactory();
     _accessTokenStore    = AccessTokenStore.Instance();
     _authenticationStore = AuthenticationStore.Instance();
     _tokens    = new List <StoredUmaAccessToken>();
     _documents = new List <StoredOfficeDocument>();
 }