public CustomOAuthAuthorizationServerProvider(
     ICredentialServer credentialServer,
     IUserServer userServer)
 {
     _credentialServer = credentialServer;
     _userServer       = userServer;
 }
 public OAuthGrantController(
     ICredentialServer credentialService,
     IUserServer userService)
 {
     _credentialService = credentialService;
     _userService       = userService;
 }