code: func (d *Flags) MakeLoggingContext(out io.Writer) context.Context {
  	ret := (&gologger.LoggerConfig{
  		Out:    out,
  		Format: gologger.PickStdFormat(out),
  	}).Use(context.Background())
  	if d.Quiet {
  		ret = logging.SetLevel(ret, logging.Warning)
  	} else if d.Verbose {
  		ret = logging.SetLevel(ret, logging.Debug)
  	} else {
  		ret = logging.SetLevel(ret, logging.Info)
  	}
  	return ret
  }
docs: // MakeLoggingContext makes a luci-go/common/logging compatible context using
  // gologger onto the given writer.
  //
  // The default logging level will be Info, with Warning and Debug corresponding
  // to quiet/verbose respectively.