all these changes

frontend/node_modules/core-js/internals/to-property-key.js

@@ -0,0 +1,10 @@
+'use strict';
+var toPrimitive = require('../internals/to-primitive');
+var isSymbol = require('../internals/is-symbol');
+
+// `ToPropertyKey` abstract operation
+// https://tc39.es/ecma262/#sec-topropertykey
+module.exports = function (argument) {
+  var key = toPrimitive(argument, 'string');
+  return isSymbol(key) ? key : key + '';
+};