@Override
    public Integer offsetComparator(String offset1, String offset2) {
      if (offset1 == null) {
        return offset2 == null ? 0 : -1;
      } else if (offset2 == null) {
        return 1;
      }
      return offset1.compareTo(offset2);
    }
System factory of Samza Sql Shell which needs to provide Consumer, Producer and Admin
samza-sql-shell/src/main/java/org/apache/samza/sql/client/impl/CliLoggingSystemFactory.java