public Operation SessionSignOut()
=> Operation.Try(async() =>
{
var sessionId = (await _sessionContext
.CurrentSessionId())
.ThrowIf(default(Guid), new GaiaException(ErrorCodes.DomainLogicError));
var userId = (await _userContext
.CurrentUserId())
.ThrowIf(default(Guid), new GaiaException(ErrorCodes.DomainLogicError));
await _logonInvalidator.InvalidateLogon(userId, sessionId);
});