class UrlUtils { UrlUtils._(); static String buildQueryString(Map? params) { if (params == null || params.isEmpty) return ''; final queryParams = {}; for (final entry in params.entries) { final value = entry.value; if (value == null) continue; if (value is String || value is num || value is bool) { queryParams[entry.key] = value.toString(); } } if (queryParams.isEmpty) return ''; return '?${Uri(queryParameters: queryParams).query}'; } }