code: func (errs *Errors) AddError(errors ...error) {
  	for _, err := range errors {
  		if err != nil {
  			if e, ok := err.(errorsInterface); ok {
  				errs.errors = append(errs.errors, e.GetErrors()...)
  			} else {
  				errs.errors = append(errs.errors, err)
  			}
  		}
  	}
  }
docs: // AddError add error to Errors struct