param { number } delayTime optionalParam returns export async function delay < T > ( delayTimeMs , value ) ; export async function delay < T > ( delayTimeMs ) ; export async function delay < T > ( delayTime , value ? ) { return new Promise ( resolve => setTimeout ( ( ) => resolve ( value ) , delayTime ) ) ; } optionalParam returns export async function immediate < T > ( value ) ; export async function immediate < T > ( ) ; export async function immediate ( value ? ) { return new Promise ( resolve => setImmediate ( ( ) => resolve ( value ) ) ) ; }