anchor.diff:          post_contract_tx_and_wait_in_chain(new_node3, PubKey3, Nonce2, ContractPubKey, contract_call_compute_tx,
                                              ContractCallComputeTx, Cfg),
       %% Check protocol version of the block with mined transaction on all nodes.
  -    %% TODO: old_node1 doesn't sync the block containing the tx.
  -    check_protocol_version_on_nodes([new_node3, new_node4, {old, old_node1}], OldProtocolVersion,
  +    %% Cannot smoke test that block with contract tx mined by new node with old protocol is synced by old_node1.
  +    check_protocol_version_on_nodes([new_node3, new_node4], OldProtocolVersion,
                                       ContractCallComputeBlockHash, ContractCallComputeBlockHeight, Cfg),
       ok.
   
  
positive.code:         post_contract_tx_and_wait_in_chain(new_node3, PubKey3, Nonce1, ContractPubKey, contract_call_tx,
                                             ContractCallTx, Cfg),
      %% Check protocol version of the block with mined transacion on all nodes.
      check_protocol_version_on_nodes([new_node3, {old, old_node1}, new_node4], OldProtocolVersion,
                                      ContractCallBlockHash, ContractCallBlockHeight, Cfg),
      %% Create contract call compute transaction.
      {ContractCallCompute, DecContractCallCompute} =
  
negative.code:     wait_for_height_syncing(TopHeight, [new_node4], {{100000, ms}, {1000, blocks}}, Cfg),
      ok = mock_pow_on_node(new_node3, Cfg),
      ok = mock_pow_on_node(new_node4, Cfg),
      %% Kill old node - syncing of blocks with contract transactions is not tested.
      aest_nodes:kill_node(old_node1, Cfg),
      %% expected_mine_rate is lowered so contract gets mined faster.
      ErlCmd = make_erl_cmd("application:set_env(aecore, expected_mine_rate, ~p)", [10]),
      ok = run_erl_cmd_on_node(new_node3, ErlCmd, Cfg),
      ok = run_erl_cmd_on_node(new_node4, ErlCmd, Cfg),
      %% Get public key of account meant to be creator of contract and make sure it has a sufficient balance by means of mining.
      {ok, 200, #{pub_key := PubKey3}} = request(new_node3, 'GetPubKey', #{}, Cfg),
      %% Balance is 0.
  