public IActionResult CheckOut(string userName)
{
IActionResult result = NoContent();
var existingVisit = _db.GetCurrentVisit(userName);
if (existingVisit == null)
{
result = NotFound();
}
else
{
existingVisit.CheckOut = DateTime.UtcNow;
_db.UpdateVisit(existingVisit);
result = Ok();
}
return(result);
}