docs: public final DeterministicKeyChain getActiveKeyChain(Script.ScriptType outputScriptType, long keyRotationTimeSecs) {
          checkState(isSupportsDeterministicChains(), "doesn't support deterministic chains");
          for (DeterministicKeyChain chain : ImmutableList.copyOf(chains).reverse())
              if (chain.getOutputScriptType() == outputScriptType
                      && chain.getEarliestKeyCreationTime() >= keyRotationTimeSecs)
                  return chain;
          return null;
      }