Express addition

node_modules/core-js/modules/_flags.js

@@ -0,0 +1,13 @@
+'use strict';
+// 21.2.5.3 get RegExp.prototype.flags
+var anObject = require('./_an-object');
+module.exports = function () {
+  var that = anObject(this);
+  var result = '';
+  if (that.global) result += 'g';
+  if (that.ignoreCase) result += 'i';
+  if (that.multiline) result += 'm';
+  if (that.unicode) result += 'u';
+  if (that.sticky) result += 'y';
+  return result;
+};