dojo FilteringSelect with cached entries

FilteringSelectClass.js

declare([
  "dojo/_base/declare",
  "dojo/store/JsonRest",
  "dojo/store/Memory",
  "dojo/store/Cache",
  "dijit/form/FilteringSelect"
], function(declare, JsonRest, Memory, Cache, FilteringSelect) {
  var _class = declare("FilteringSelectClass", null, {
    createFileringSelect: function(domNode) {
      var memoryStore = new Memory(),
          restStore = new JsonRest({
            target: "uri/to/get/entries/as/json/list"
          }),
          cachedStore = new Cache(restStore, memoryStore);
          // execute query and cache list of entries in memory store
          cachedStore.query();
          
          var widget = new FilteringSelect({
            id: "unique_id",
            name: "widget_name",
            hasDownArrow: true,
            invalidMessage: "No element found",
            searchAttr: "the name of attribute to filter results",
            store: memoryStore
          });
          if (domNode) {
            widget.placeAt(domNode);
          }
    }
  });
  return _class;
});

FilteringSelectWithCachedEntries

dijit.form.FilteringSelect is a combo box with functionality to query store and filter results by user input.
Usually as store is used dojox.data.QueryReadStore.
Alternative is to use JsonRest to query once the backend and cache the data in memory store.
JsonRest has methods get nad search. Get would be cached and serach wouldn't.
The solution is to assign memory store to FilteringSelect filled out entries from JsonRest.