getQueryParameters method
Generates the query parameters string for the API request.
Returns a string containing the query parameters in the format "key1=value1&key2=value2&...". The values are URL-encoded.
Implementation
String getQueryParameters() {
final map = toMap();
return map.entries
.map((e) => "${e.key}=${Uri.encodeQueryComponent(e.value)}")
.join("&");
}