code: function (value) {
          if (is(value).a(Object)) value = Unirest.serializers.form(value)
          if (!value.length) return $this
          $this.options.url += (does($this.options.url).contain('?') ? '&' : '?') + value
          return $this
        }
docs: Serialize value as querystring representation, and append or set on `Request.options.url`
  
  @param  {String|Object} value
  @return {Object}