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