code: public PactDslRequestWithoutPath withFileUpload(String partName, String fileName, String fileContentType, byte[] data)
        throws IOException {
        setupFileUpload(partName, fileName, fileContentType, data);
        return this;
      }
docs: Sets up a file upload request. This will add the correct content type header to the request
  @param partName This is the name of the part in the multipart body.
  @param fileName This is the name of the file that was uploaded
  @param fileContentType This is the content type of the uploaded file
  @param data This is the actual file contents