docs: @Override
      public Script freshOutputScript(KeyPurpose purpose) {
          DeterministicKey followedKey = getKey(purpose);
          ImmutableList.Builder<ECKey> keys = ImmutableList.<ECKey>builder().add(followedKey);
          for (DeterministicKeyChain keyChain : followingKeyChains) {
              DeterministicKey followingKey = keyChain.getKey(purpose);
              checkState(followedKey.getChildNumber().equals(followingKey.getChildNumber()), "Following keychains should be in sync");
              keys.add(followingKey);
          }
          List<ECKey> marriedKeys = keys.build();
          Script redeemScript = ScriptBuilder.createRedeemScript(sigsRequiredToSpend, marriedKeys);
          return ScriptBuilder.createP2SHOutputScript(redeemScript);
      }