 only  Async:  try { let type = await fileGuesser.guessByFileSignature('./test/files/png.png'); console.log(type); // 'image/png' or 'unknown' on fail } catch(err){}  Promise:  fileGuesser.guessByFileSignature('./test/files/png.png').then((type)=>{ console.log(type); // 'image/png' or 'unknown' on fail }).catch((err)=>{});  G