code: func newPluginGetter(command string, settings environment.EnvSettings, name, base string) Constructor {
  	return func(URL, CertFile, KeyFile, CAFile string) (Getter, error) {
  		result := &pluginGetter{
  			command:  command,
  			certFile: CertFile,
  			keyFile:  KeyFile,
  			cAFile:   CAFile,
  			settings: settings,
  			name:     name,
  			base:     base,
  		}
  		return result, nil
  	}
  }
docs: // newPluginGetter constructs a valid plugin getter