code: func NewConfig() *Config {
  	return &Config{
  		Preferences: *NewPreferences(),
  		Clusters:    make(map[string]*Cluster),
  		AuthInfos:   make(map[string]*AuthInfo),
  		Contexts:    make(map[string]*Context),
  		Extensions:  make(map[string]runtime.Object),
  	}
  }
docs: // NewConfig is a convenience function that returns a new Config object with non-nil maps