code: function format(obj) {
    var parameters = obj.parameters
    var type = obj.type
  
    if (!type || typeof type !== 'string' || !tokenRegExp.test(type)) {
      throw new TypeError('invalid type')
    }
  
    // start with normalized type
    var string = String(type).toLowerCase()
  
    // append parameters
    if (parameters && typeof parameters === 'object') {
      var param
      var params = Object.keys(parameters).sort()
  
      for (var i = 0; i < params.length; i++) {
        param = params[i]
  
        var val = param.substr(-1) === '*'
          ? ustring(parameters[param])
          : qstring(parameters[param])
  
        string += '; ' + param + '=' + val
      }
    }
  
    return string
  }
docs: Format object to Content-Disposition header.
  
  @param {object} obj
  @param {string} obj.type
  @param {object} [obj.parameters]
  @return {string}
  @api private