code: public void init(String txn, TransactionConfig btc) {
          FilterProcessor fp = null;
  
          if (btc.getFilter() != null) {
              fp = new FilterProcessor(txn, btc);
          }
  
          synchronized (filterMap) {
              // Check if old filter processor needs to be removed
              FilterProcessor oldfp = filterMap.get(txn);
              if (oldfp != null) {
                  globalExclusionFilters.remove(oldfp);
                  btxnFilters.remove(oldfp);
              }
  
              if (fp != null) {
                  // Add new filter processor
                  filterMap.put(txn, fp);
                  if (fp.isIncludeAll()) {
                      globalExclusionFilters.add(fp);
                  } else {
                      btxnFilters.add(fp);
                  }
              } else {
                  filterMap.remove(txn);
              }
          }
      }
docs: This method initialises the filter manager with the supplied
  transaction configuration.
  
  @param txn The transaction name
  @param btc The configuration