anchor.diff:                 GasTx3 = aetx:gas(aetx_sign:tx(STx3)),
   
                  ?assert(GasTx2 > GasTx1),
  -               ?assert(GasTx2 > GasTx3),
  -               ?assert(GasTx1 < GasTx3),
  +               ?assert(GasTx3 > GasTx1),
  +               {MinGasTx, MaxGasTx} = 
  +                   case GasTx2 > GasTx3 of
  +                       true -> { {STx3, GasTx3}, {STx2, GasTx2} };
  +                       false ->  { {STx2, GasTx2}, {STx3, GasTx3} }
  +                     end,
   
                  %% Push all txs to the pool.
                  ?assertEqual(ok, aec_tx_pool:push(STx1)),
  
positive.code: 
                 %% Prepare 3 txs:
                 %% 1st tx has the lowest gas
                 %% 2nd tx has greater gas than 1st and 3rd tx
                 STx1 = a_signed_tx(me, PK1, 1, 100),
                 STx2 = signed_ct_create_tx(PK2, 1, 100, 1000),
                 STx3 = signed_ct_call_tx(PK3, 1, 100, 1000),
  
negative.code:                aec_tx_pool:restore_mempool(),
  
                 %% Get only 2 txs, the 1st + 2nd or 1st + 3rd.
                 {_, Max} = MaxGasTx,
                 {ok, STxs1} = aec_tx_pool:get_candidate(GasTx1 + Max, aec_chain:top_block_hash()),
                 ?assert(lists:member(STx1, STxs1) and (lists:member(STx2, STxs1) or lists:member(STx3, STxs1))),
  
                 aec_tx_pool:restore_mempool(),
  