address review comments

Author: yharish991-brcm

pivnet.go

@@ -127,8 +127,10 @@ func NewAccessTokenOrLegacyToken(token string, host string, skipSSLValidation bo
 // createProxyAuthTransport creates an HTTP transport with proxy authentication
 func createProxyAuthTransport(config ClientConfig) (http.RoundTripper, error) {
 	// Validate required fields for proxy authentication
-	if config.ProxyAuthConfig.ProxyURL == "" || config.ProxyAuthConfig.Username == "" || config.ProxyAuthConfig.Password == "" {
-		return nil, fmt.Errorf("proxy URL, username, and password are required when proxy authentication is specified")
+	// Note: For Basic auth, username and password can be empty (though both empty means no auth header)
+	// For SPNEGO, username, password, and proxyURL are all required (validated in NewSPNEGOProxyAuth)
+	if config.ProxyAuthConfig.ProxyURL == "" {
+		return nil, fmt.Errorf("proxy URL is required when proxy authentication is specified")
 	}
 
 	// Parse proxy URL