@Override
  protected String formatLogFilters(List<Filter> logFilters) {
    return String.format("FilterList OR (%d/%d): %s", logFilters.size(), this.size(),
      logFilters.toString());
  }
Save previous return code and previous cell for every filter in filter list. For MUST_PASS_ONE,
we use the previous return code to decide whether we should pass current cell encountered to
the filter. For MUST_PASS_ALL, the two list are meaningless.
hbase-client/src/main/java/org/apache/hadoop/hbase/filter/FilterListWithOR.java