/**
  * {@inheritdoc}
  */
 public function update($model, array $attributes)
 {
     if (!$model->exists) {
         throw new \RuntimeException('Cannot update non-existant model');
     }
     return parent::update($model, $attributes);
 }
 /**
  * @param \Illuminate\Database\Connection $db
  * @param \anlutro\LaravelValidation\ValidatorInterface $validator
  */
 public function __construct(Connection $db, ValidatorInterface $validator = null)
 {
     if ($this->table === null) {
         $class = get_class($this);
         throw new \RuntimeException("Property {$class}::\$table must be defined.");
     }
     parent::__construct($validator);
     $this->setConnection($db);
     if ($validator) {
         $validator->replace('table', $this->table);
     }
 }