Types Are Sets

function timeout(ms: number): Promise<never> {  return new Promise((_, reject) =>    setTimeout(() => reject(new Error("Timeout elapsed")), ms)  )}

async function fetchPriceWithTimeout(  tickerSymbol: string): Promise<number> {  const stock = await Promise.race([    fetchStock(tickerSymbol), // `Promise<{ price: number }>`    timeout(3000)             // `Promise<never>`  ])  return stock.price // { price: number } | never                     //   => { price: number }}