code: public void addFilter(String filterName)
      {
          _hasFilters = true;
          //PM93069 Start
          if(!WCCustomProperties.DENY_DUPLICATE_FILTER_IN_CHAIN){
              _filterNames.add(filterName); 
          }
          else { 
  
              if(! _filterNames.contains(filterName)){ // if unique then add in the chain
                  _filterNames.add(filterName);
              }
              else{
                  if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled()&&logger.isLoggable (Level.FINE))
                      logger.logp(Level.FINE, CLASS_NAME,"init", "filter already in chain ->"+ filterName);
  
              }
          }    //PM93069 End
      }
docs: Adds a filter name to the name vector for this chain
  
  @param the filter name to add