text: 
  function pad(num, size){ return ('000000000' + num).substr(-size); }
  
  function debounce(callback, time) {
    let interval;
    return (...args) => {
      clearTimeout(interval);
      interval = setTimeout(() => {
        interval = null;
        callback(...args);
      }, time);
    };
  }
  
  module.exports = {pad, debounce};