public IObservable <Result <SessionEntity> > CreateSession(ValidateTokenPostCommand command) =>
_sessionRemoteDataSource.CreateRequestToken()
.ExtractResult()
.Select(token =>
new ValidateTokenPostCommand(
command.Username, command.Password, token.RequestToken.Value))
.SelectMany(validateCommand =>
_sessionRemoteDataSource.ValidateRequestToken(validateCommand))
.ExtractResult()
.Select(validation =>
public IObservable <Result <TokenValidationDto> > ValidateRequestToken(ValidateTokenPostCommand command) => Api.ValidateRequestToken(command).ToResult();