getJointGiver method
Will get a collection of PcoGivingPerson objects (expecting many)
using a path like this: https://api.planningcenteronline.com/giving/v2/pledges/1/joint_giver
Implementation
Future<PcoCollection<PcoGivingPerson>> getJointGiver(
{PcoGivingPersonQuery? query}) async {
query ??= PcoGivingPersonQuery();
var url = '$apiEndpoint/joint_giver';
return PcoCollection.fromApiCall<PcoGivingPerson>(url,
query: query, apiVersion: apiVersion);
}