docs: public String getUniqueID() {
          // return null so that this token does not change the uniqueness, 
          // all static attributes from the default tokens.
          String[] cacheKeyArray = getAttributes(AttributeNameConstants.WSCREDENTIAL_CACHE_KEY);
  
          if (cacheKeyArray != null && cacheKeyArray[0] != null) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
                  Tr.debug(tc, "Found cache key in Authz token: " + cacheKeyArray[0]);
              return cacheKeyArray[0];
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled())
              Tr.debug(tc, "No unique cache key found in token.");
          return null;
      }