-const copyFilePromise = promisify2WithVoid<string, string>(copyFile)
-const readFileBufferPromise = promisify1<string, Buffer>(readFile)
-const unlinkPromise = promisify1WithVoid<string>(unlink)
-const renamePromise = promisify2WithVoid<string, string>(rename)
-const writeFilePromise = promisify2WithVoid<string, any>(writeFile)
-const readdirPromise = promisify1<string, string[]>(readdir)
-const mkdirpPromise = promisify1<string, string>(mkdirp)
-// we cannot modify the Promise types, so we should make the promisify instance check mkdirp