withQueryParam method
Returns a new Uri with key=value added (or replaced) in the query.
Uri.parse('https://example.com?page=1').withQueryParam('q', 'dart')
// https://example.com?page=1&q=dart
Implementation
Uri withQueryParam(String key, String value) {
final params = Map<String, String>.from(queryParameters);
params[key] = value;
return replace(queryParameters: params);
}