code: def remove_tmp_prefix_from_filename(filename):
      
      if not filename.startswith(dju_settings.DJU_IMG_UPLOAD_TMP_PREFIX):
          raise RuntimeError(ERROR_MESSAGES['filename_hasnt_tmp_prefix'] % {'filename': filename})
      return filename[len(dju_settings.DJU_IMG_UPLOAD_TMP_PREFIX):]
docs: Remove tmp prefix from filename.