function exists(what) {
    return new Promise(resolve => {
        promfs.stat(what)
            .then(() => resolve(true))
            .catch(err => resolve(false));
    });
}
/**
 * if the file exists this promise resolves true, else resolves false
 * @param what {string} file name
 * @return {Promise<boolean>}
 */
if the file exists this promise resolves true, else resolves false
@param what {string} file name
@return {Promise}
if the file exists this promise resolves true else resolves false @param what { string } file name @return { Promise }
function exists(what) {
    return new Promise(resolve => {
        promfs.stat(what)
            .then(() => resolve(true))
            .catch(err => resolve(false));
    });
}
function exists ( what ) { return new Promise ( resolve => { promfs . stat ( what ) . then ( ( ) => resolve ( true ) ) . catch ( err => resolve ( false ) ) ; } ) ; }
if the file exists this promise resolves true, else resolves false
 @param what {string} file name
 @return {Promise<boolean>}
if the file exists this promise resolves true else resolves false @param what { string } file name @return { Promise<boolean > }