function checkThrow(property, opts) {
  opts = opts || {};
  if (opts.quiet === undefined) {
    opts.quiet = true;
  }

  return functor.run(functor.map(check(property, opts), function (r) {
    if (r !== true) {
      if (r.exc instanceof Error) {
        r.exc.message = formatFailedCase(r);
        throw r.exc;
      } else {
        throw new Error(formatFailedCase(r));
      }
    }
  }));
}
- `assert(prop: property, opts: checkoptions?) : void`

      Same as `check`, but throw exception if property doesn't hold.