code: public function update(array $fields = [])
      {
          $keys = [];
          foreach ($fields as $key => $value) {
              array_set($this->fields, $key, $value);
              $keys[] = $key;
          }
  
          return $this->save($keys);
      }
docs: Update model.
  
  @param array $fields
  
  @return bool