Backport: add mixin polyfill to support CiviCRM 5.75+#21

erawat merged 1 commit intomastercompucorp/io.compuco.paymentprocessingcore:masterfrom

backport/5.75-mixin-polyfillcompucorp/io.compuco.paymentprocessingcore:backport/5.75-mixin-polyfillCopy head branch name to clipboard