code: public function addError($model, $attribute, $message, $params = [])
      {
          $params['attribute'] = $model->getAttributeLabel($attribute);
          if (!isset($params['value'])) {
              $value = $model->$attribute;
              if (is_array($value)) {
                  $params['value'] = 'array()';
              } elseif (is_object($value) && !method_exists($value, '__toString')) {
                  $params['value'] = '(object)';
              } else {
                  $params['value'] = $value;
              }
          }
          $model->addError($attribute, $this->formatMessage($message, $params));
      }
docs: Adds an error about the specified attribute to the model object.
  This is a helper method that performs message selection and internationalization.
  @param \yii\base\Model $model the data model being validated
  @param string $attribute the attribute being validated
  @param string $message the error message
  @param array $params values for the placeholders in the error message