def build_draft_upload(key)
        cw_uploader = self.send(key)
        file = File.new(cw_uploader.file.path) if cw_uploader.file
        existing_upload = self.draft.draft_uploads.where(:draftable_mount_column => key).first
        draft_upload = existing_upload.nil? ? DraftUpload.new : existing_upload
        draft_upload.file_data = file
        draft_upload.draftable_mount_column = key
        draft_upload
      end
def build_draft_upload(key)
        cw_uploader = self.send(key)
        file = File.new(cw_uploader.file.path) if cw_uploader.file
        existing_upload = self.draft.draft_uploads.where(:draftable_mount_column => key).first
        draft_upload = existing_upload.nil? ? DraftUpload.new : existing_upload
        draft_upload.file_data = file
        draft_upload.draftable_mount_column = key
        draft_upload
      end
Get a reference to the CarrierWave uploader mounted on the
 current draftable object, grab the file in it, and shove
 that file into a new DraftUpload.

 @param [String] key the attribute where the CarrierWave uploader
   is mounted.
 @return [DraftUpload] containing the file in the uploader.