docs: function _removeIdlePromise(idleQueue, promise) {
      if (!promise) return;
  
      // remove timeout if exists
      if (promise._timeoutObj)
          clearTimeout(promise._timeoutObj);
  
      // remove handle-nr if exists
      if (idleQueue._pHM.has(promise)) {
          const handle = idleQueue._pHM.get(promise);
          idleQueue._hPM.delete(handle);
          idleQueue._pHM.delete(promise);
      }
  
      // remove from queue
      idleQueue._iC.delete(promise);
  }