code: public static void t(Class<?> clz, int probeId) {
          if (clz != null) {
              int index = probeId & PROBE_SIZE_MASK;
              if (PROBE_ARRAY[index] != clz) {
                  PROBE_ARRAY[index] = clz;
                  t(clz);
              }
          }
      }
docs: Touch method, which also accepts probe id. The id can be used to optimize
  execution.
  
  The current optimization is as follows: we check if index at probeId
  location is set; if yes, then we do nothing, but if not, we set it and
  invoke original touch method. As we use limited size of probe array, we
  have to check length as we may have more probes than array allows.