name : wp-polyfill-node-contains.js (function() { function contains(node) { if (!(0 in arguments)) { throw new TypeError('1 argument is required'); } do { if (this === node) { return true; } } while (node = node && node.parentNode); return false; } // IE if ('HTMLElement' in this && 'contains' in HTMLElement.prototype) { try { delete HTMLElement.prototype.contains; } catch (e) {} } if ('Node' in this) { Node.prototype.contains = contains; } else { document.contains = Element.prototype.contains = contains; } }());