code: private static String getToken(URI blobId) {
          String[] parts = blobId.getSchemeSpecificPart().split("/");
          if (parts.length == 2) {
              return parts[1];
          } else if (parts.length == 4) {
              return parts[1] + "+"  + uriDecode(parts[2]) + "+"
                      + uriDecode(parts[3]);
          } else {
              throw new IllegalArgumentException("Malformed token-as-blobId: "
                      + blobId);
          }
      }
docs: Converts a token-as-blobId back to a token.
  
  @param blobId the blobId to convert.
  @return the resulting object or datastream token.