anchor.diff:                                         gas_price => 1,
                                          amount    => Value,
                                          fee       => Fee}, S),
  -    {error, _} = sign_and_apply_transaction(CallTx, aect_test_utils:priv_key(Acc1, S), S),
  +    {error, _, _} = sign_and_apply_transaction(CallTx, aect_test_utils:priv_key(Acc1, S), S),
       Env = aetx_env:tx_env(_Height = 1),
       {error, insufficient_funds} = aetx:check(CallTx, aect_test_utils:trees(S), Env),
       ok.
  
positive.code:                  }, maps:without([height, return_gas_used, return_logs], Options)), S),
      Height   = maps:get(height, Options, 1),
      PrivKey  = aect_test_utils:priv_key(Caller, S),
      {ok, S1} = sign_and_apply_transaction(CallTx, PrivKey, S, Height),
      CallKey  = aect_call:id(Caller, Nonce, ContractKey),
      CallTree = aect_test_utils:calls(S1),
      Call     = aect_call_state_tree:get_call(ContractKey, CallKey, CallTree),
      Result   =
          case aect_call:return_type(Call) of
              ok     -> {ok, Res} = aeso_heap:from_binary(Type, aect_call:return_value(Call)),
                        Res;
              error  -> {error, aect_call:return_value(Call)};
              revert -> revert
          end,
      Result1 = case maps:get(return_logs, Options, false) of
                  true -> {Result, aect_call:log(Call)};
                  false -> Result end,
      case maps:get(return_gas_used, Options, false) of
          false -> {Result1, S1};
          true  -> {{Result1, aect_call:gas_used(Call)}, S1}
      end.
  
  account_balance(PubKey, S) ->
  
negative.code:     Tx   = aect_test_utils:call_tx(Acc1, IdC, #{gas_price => 0}, S),
      ?assertEqual(0, aect_call_tx:gas_price(aetx:tx(Tx))),
  
      {error, _, _} = sign_and_apply_transaction(Tx, aect_test_utils:priv_key(Acc1, S), S),
      Env           = aetx_env:tx_env(_Height = 1),
      {error, too_low_gas_price} = aetx:check(Tx, aect_test_utils:trees(S), Env),
      ok.
  
  