code: func NewLogSet(prefix string, debug bool) (stderr, diagnostic, stdout *Logger) {
  	stderr = New(os.Stderr, prefix, debug)
  	diagnostic = New(os.Stderr, prefix, debug)
  	// Debug not used for stdout.
  	stdout = New(os.Stdout, prefix, false)
  
  	return stderr, diagnostic, stdout
  }
docs: // NewLogSet returns a set of Loggers for commonly used output streams: errors,
  // diagnostics, stdout. The error and stdout streams should generally never be
  // suppressed. diagnostic can be suppressed by setting the output to
  // ioutil.Discard. If an output destination is not needed, one can simply
  // discard it by assigning it to '_'.