如何在招摇中定义原型上传的多部分/表单数据

I'm having a hard time figuring this out.

We have defined some proto files as our contract for swagger, and I can't quite figure out how to define a multipart/form-data field on the request object.

We are using proto3 and Swagger 2.0

The request object is pretty straight forward.

message ImportRequest {
   bytes file = 1;
}

The above isn't the result I'm looking for ... it results in this

What I need to generate from the proto file above is a swagger output like so..

 paths:
  /upload:
    post:
      summary: Uploads a file.
      consumes:
        - multipart/form-data
      parameters:
        - in: formData
          name: upfile
          type: file
          description: The file to upload.

The above is from here -> https://swagger.io/docs/specification/2-0/file-upload/

Any thoughts?