code: func (c TLSClientConfig) String() string {
  	cc := sanitizedTLSClientConfig{
  		Insecure:   c.Insecure,
  		ServerName: c.ServerName,
  		CertFile:   c.CertFile,
  		KeyFile:    c.KeyFile,
  		CAFile:     c.CAFile,
  		CertData:   c.CertData,
  		KeyData:    c.KeyData,
  		CAData:     c.CAData,
  	}
  	// Explicitly mark non-empty credential fields as redacted.
  	if len(cc.CertData) != 0 {
  		cc.CertData = []byte("--- TRUNCATED ---")
  	}
  	if len(cc.KeyData) != 0 {
  		cc.KeyData = []byte("--- REDACTED ---")
  	}
  	return fmt.Sprintf("%#v", cc)
  }
docs: // String implements fmt.Stringer and sanitizes sensitive fields of
  // TLSClientConfig to prevent accidental leaking via logs.