anchor.diff:  
       {ok, #{<<"event">> := <<"withdraw_locked">>}} = wait_for_channel_event(SenderConnPid, info, Config),
       {ok, #{<<"event">> := <<"withdraw_locked">>}} = wait_for_channel_event(AckConnPid, info, Config),
  -
  -
  -    ok = ?WS:stop(SenderConnPid),
  -    ok = ?WS:stop(AckConnPid),
  +    ok = ?WS:unregister_test_for_channel_events(SenderConnPid, [sign, info, on_chain_tx]),
  +    ok = ?WS:unregister_test_for_channel_events(AckConnPid, [sign, info, on_chain_tx]),
       ok.
   
   sc_ws_contracts(Config) ->
  
positive.code: %% channel websocket endpoints
  -export(
     [sc_ws_timeout_open/1,
      sc_ws_open/1,
      sc_ws_update/1,
      sc_ws_update_fails_and_close/1,
      sc_ws_send_messages_and_close/1,
      sc_ws_conflict_and_close/1,
      sc_ws_close/1,
      sc_ws_close_mutual_initiator/1,
      sc_ws_close_mutual_responder/1,
      sc_ws_leave/1,
      sc_ws_reestablish/1,
      sc_ws_deposit_initiator_and_close/1,
      sc_ws_deposit_responder_and_close/1,
      sc_ws_withdraw_initiator_and_close/1,
      sc_ws_withdraw_responder_and_close/1,
      sc_ws_contracts/1,
      sc_ws_oracle_contract/1,
      sc_ws_nameservice_contract/1,
  
negative.code:          responder,
           initiator,
           responder]),
      ok.
  
  channel_conflict(#{initiator := IConnPid, responder :=RConnPid},
  