docs: public boolean enlist(BeanO beanO)
      {
          final boolean isTraceOn = TraceComponent.isAnyTracingEnabled();
          if (isTraceOn && tc.isEntryEnabled())
              Tr.entry(tc, "enlist : " + beanO);
          ensureActive();
          BeanO oldBeanO = ivBeanOs.put(beanO.beanId, beanO);
          if (oldBeanO == null) {
              ivBeanOList.add(beanO);
              if (isTraceOn && tc.isEntryEnabled())
                  Tr.exit(tc, "enlist : true");
              return true;
          }
          if (isTraceOn && tc.isEntryEnabled())
              Tr.exit(tc, "enlist : false");
          return false;
      }