code: public static String compareChecksum(String providerChecksum,
                                           String spaceId,
                                           String contentId,
                                           String checksum)
          throws ChecksumMismatchException {
          if (!providerChecksum.equals(checksum)) {
              String err = "Content " + contentId + " was added to space " +
                           spaceId + " but the checksum, either provided or computed " +
                           "enroute, (" + checksum + ") does not match the checksum " +
                           "computed by the storage provider (" + providerChecksum +
                           "). This content should be retransmitted.";
              log.warn(err);
              throw new ChecksumMismatchException(err, NO_RETRY);
          }
          return providerChecksum;
      }
docs: Determines if two checksum values are equal
  
  @param providerChecksum The checksum provided by the StorageProvider
  @param spaceId          The Space in which the content was stored
  @param contentId        The Id of the content
  @param checksum         The content checksum, either provided or computed
  @throws ChecksumMismatchException if the included checksum does not match
  the storage provider generated checksum
  @returns the validated checksum value from the provider