code: func (kr *GroupResolver) GetAllKeys() []Key {
  	kr.RLock()
  	defer kr.RUnlock()
  	var keys []Key
  	for name := range kr.keyMap {
  		for _, key := range kr.keyMap[name] {
  			keys = append(keys, key)
  		}
  	}
  	return keys
  }
docs: // GetAllKeys returns a list of all the keys stored in the resolver.