docs: public List<DeterministicKeyChain> getActiveKeyChains(long keyRotationTimeSecs) {
          checkState(isSupportsDeterministicChains(), "doesn't support deterministic chains");
          List<DeterministicKeyChain> activeChains = new LinkedList<>();
          for (DeterministicKeyChain chain : chains)
              if (chain.getEarliestKeyCreationTime() >= keyRotationTimeSecs)
                  activeChains.add(chain);
          return activeChains;
      }