vendors/tempy.js/rmkids
    var rmkids = (p, options, cb) => {
      assert(p);
      assert(options);
      assert(typeof cb === "function");
      options.readdir(p, (er, files) => {
        if (er)
          return cb(er);
        let n = files.length;
        if (n === 0)
          return options.rmdir(p, cb);
        let errState;
        files.forEach((f) => {
          rimraf(path2.join(p, f), options, (er2) => {
            if (errState)
              return;
            if (er2)
              return cb(errState = er2);
            if (--n === 0)
              options.rmdir(p, cb);
          });
        });
      });
    };