code: function prefixKeypath(obj, prefix) {
    const prefixed = {};
  
    if (!prefix) {
      return obj;
    }
  
    prefix += '.';
  
    for (const key in obj) {
      if (hasOwn(obj, key)) {
        prefixed[prefix + key] = obj[key];
      }
    }
  
    return prefixed;
  }
docs: TODO this is legacy. sooner we can replace the old adaptor API the better /* istanbul ignore next