docs: @Override
      public int[] getThreadIdentitySecurityAndRRSSupport(String identifier) {
          WSManagedConnectionFactoryImpl mcf1;
          if (jdbcDriverSvc.loadFromApp()) {
              final boolean trace = TraceComponent.isAnyTracingEnabled();
  
              // data source class is loaded from thread context class loader
              if (identifier == null) {
                  ClassLoader tccl = priv.getContextClassLoader();
                  identifier = connectorSvc.getClassLoaderIdentifierService().getClassLoaderIdentifier(tccl);
                  // TODO better error handling when thread context class loader does not have an identifier
              }
              mcf1 = mcfPerClassLoader.get(identifier);
          } else
              mcf1 = mcf;
  
          DatabaseHelper dbHelper = mcf1.getHelper();
          return new int[] { dbHelper.getThreadIdentitySupport(), dbHelper.getThreadSecurity() ? 1 : 0, dbHelper.getRRSTransactional() ? 1 : 0 };
      }