A StripeRequest for uploading a file using MimeType.MultipartForm.
See File upload guide
The HTTP headers attached to this request
The type(Get/Post/Delete) of this request.
The MimeType of this request, determines the header and body format for a POST request
Additional HTTP headers attached if this is a POST request
A range of HTTP response code indicating this request should be retried
Whether the response should be cached or not
The url of the request, could be concatenated with query params
Writes the body of a POST request with OutputStream, left empty for non-POST requests