code: public function setFormValues($key = null)
      {
          if (!isset($_POST[get_class($this)])) {
              return true;
          }
          $base = $_POST[get_class($this)];
          if (is_null($key) or $key === 'primary') {
              if (!empty($base)) {
                  $this->attributes = $base;
              }
          } else {
              $key = md5($key);
              if (!empty($base[$key])) {
                  $this->attributes = $base[$key];
              }
          }
  
          return $this->validate();
      }
docs: @param unknown $key (optional)
  
  @return unknown