code: func getSecurityScopes(ss raml.DefinitionChoice) ([]string, error) {
  	scopes := []string{}
  
  	// check if there is scopes
  	v, ok := ss.Parameters["scopes"]
  	if !ok {
  		return scopes, nil
  	}
  
  	// cast it to []string, return error if failed
  	scopesArr, ok := v.([]interface{})
  	if !ok {
  		return scopes, fmt.Errorf("scopes must be array")
  	}
  
  	// build []string
  	for _, s := range scopesArr {
  		scopes = append(scopes, s.(string))
  	}
  	return scopes, nil
  }
docs: // get scopes of a security scheme as []string