function urlHasHttpsScheme (url) {
  return (
    (
      typeof url === 'string' &&
      url[5] === ':' &&
      url[0] === 'h' &&
      url[1] === 't' &&
      url[2] === 't' &&
      url[3] === 'p' &&
      url[4] === 's'
    ) ||
    url.protocol === 'https:'
  )
}
@param {string|URL} url
@returns {boolean}