1. async function poll(fn, validate, interval = 2500) {
    2.   const resolver = async (resolve, reject) => {
    3.     try { // catch any error thrown by the "fn" function
    4.       const result = await fn(); // fn does not need to be asynchronous or return promise
    5.       // call validator to see if the data is at the state to stop the polling
    6.       const valid = validate(result);
    7.       if (valid === true) {
    8.         resolve(result);
    9.       } else if (valid === false) {
    10.         setTimeout(resolver, interval, resolve, reject);
    11.       } // if validator returns anything other than "true" or "false" it stops polling
    12.     } catch (e) {
    13.       reject(e);
    14.     }
    15.   };
    16.   return new Promise(resolver);
    17. }