code: function bytes(b) {
      if (!readable) return b;
  
      var tb = ((1 << 30) * 1024)
        , gb = 1 << 30
        , mb = 1 << 20
        , kb = 1 << 10
        , abs = Math.abs(b);
  
      if (abs >= tb) return (Math.round(b / tb * 100) / 100) + 'tb';
      if (abs >= gb) return (Math.round(b / gb * 100) / 100) + 'gb';
      if (abs >= mb) return (Math.round(b / mb * 100) / 100) + 'mb';
      if (abs >= kb) return (Math.round(b / kb * 100) / 100) + 'kb';
  
      return b + 'b';
    }
docs: Make the bytes human readable if needed.
  
  @param {Number} b Bytes
  @returns {String|Number}
  @api private