code: function idleLoop(deadline) {
    var
      length = getLength(qidle, qidlex),
      didTimeout = deadline.didTimeout
    ;
    if (length) {
      // reschedule upfront next idle callback
      requestIdleCallback(idleLoop, {timeout: next.maxIdle});
      // this prevents the need for a try/catch within the while loop
      // reassign qidlex cleaning current idle queue
      qidlex = qidle.splice(0, didTimeout ? 1 : length);
      while (qidlex.length && (didTimeout || deadline.timeRemaining()))
        exec(qidlex.shift());
    } else {
      // all idle callbacks have been executed
      // we can actually stop asking for idle operations
      idleRunning = false;
    }
  }
docs: responsible for centralized requestIdleCallback operations