/**
* Restituisce un utente in base a criteri variabili, specificati in $criteria.
*
* @param array $criteria
* @return \Illuminate\Database\Eloquent\Model|null|static
*/
private function findBy(array $criteria)
{
$users = User::query();
foreach ($criteria as $fieldName => $fieldValue) {
$users->where($fieldName, '=', $fieldValue);
}
return $users->first();
}
