Fix mutation_ops set

Author: Baltazore

snippets/updating-data/create-record/handler.js

@@ -3,7 +3,8 @@ import { recordIdentifierFor } from '@ember-data/store';
 import { serializeResources } from '@ember-data/json-api/request';
 
 const updatesHandler = {
-  MUTATION_OPS = new Set(['createRecord', 'updateRecord']);
+  MUTATION_OPS: new Set(['createRecord', 'updateRecord']),
+
   request(context, next) {
     if (!MUTATION_OPS.has(context.request.op)) {
       // Not a mutation, do nothing

snippets/updating-data/save-record/handler.js

@@ -3,7 +3,8 @@ import { recordIdentifierFor } from '@ember-data/store';
 import { serializeResources } from '@ember-data/json-api/request';
 
 const updatesHandler = {
-  MUTATION_OPS = new Set(['createRecord', 'updateRecord']);
+  MUTATION_OPS: new Set(['createRecord', 'updateRecord']),
+
   request(context, next) {
     if (!MUTATION_OPS.has(context.request.op)) {
       // Not a mutation, do nothing