function isstats(obj) {
  // not even an object
  if (obj === null || typeof obj !== 'object') {
    return false
  }

  // genuine fs.Stats
  if (obj instanceof Stats) {
    return true
  }

  // quack quack
  return 'atime' in obj && toString.call(obj.atime) === '[object Date]'
    && 'ctime' in obj && toString.call(obj.ctime) === '[object Date]'
    && 'mtime' in obj && toString.call(obj.mtime) === '[object Date]'
    && 'ino' in obj && typeof obj.ino === 'number'
    && 'size' in obj && typeof obj.size === 'number'
}
Determine if object is a Stats object.

@param {object} obj
@return {boolean}
@api private