getSong method
Will get a collection of PcoServicesSong objects (expecting one)
using a path like this: https://api.planningcenteronline.com/services/v2/service_types/1/plans/1/items/1/song
Implementation
Future<PcoCollection<PcoServicesSong>> getSong(
{PcoServicesSongQuery? query}) async {
query ??= PcoServicesSongQuery();
var url = '$apiEndpoint/song';
return PcoCollection.fromApiCall<PcoServicesSong>(url,
query: query, apiVersion: apiVersion);
}