public async Task <User> FilterAsync(UserLoginFindModel model)
 {
     return(await Collection.Find(ByUserLogin(model)).SingleOrDefaultAsync());
 }
 private FilterDefinition <User> ByUserLogin(UserLoginFindModel model)
 {
     return(Query.Filter.And(ByLogin(model.Login), ByPassword(model.Password)));
 }
 public User Filter(UserLoginFindModel model)
 {
     return(Collection.Find(ByUserLogin(model)).SingleOrDefault());
 }