supportsTransitionEnd() {\n    return Boolean(TRANSITION_END)\n  },\n\n  isElement(obj) {\n    return (obj[0] || obj).nodeType\n  },\n\n  typeCheckConfig(componentName, config, configTypes) {\n    for (const property in configTypes) {\n      if (Object.prototype.hasOwnProperty.call(configTypes, property)) {\n        const expectedTypes = configTypes[property]\n        const value = config[property]\n        const valueType = value && Util.isElement(value) ?\n          'element' : toType(value)\n\n        if (!new...