code: function bytes(input, name, min, max) {
    if (typeof input === 'string') input = bts(input);
    if (name && (input < min || input > max)) 
      throw new Error(name + ' was out of range, must be between ' 
        + bytes(min) + ' and ' + bytes(max));
    return input;
  }
docs: ## bytes
  
  @param  {string|number} input Either a string like 1MB or a number of bytes
  @param  {string=} name        A name to enable validation
  @param  {number=} min         The minimum number of bytes
  @param  {number=} max         The maximum number of bytes
  @return {number}              The number of bytes
  @api private