Depois de fazer este exercício não consigo adicionar ou apagar as negociações. No console mostra isso:
Quando entro pela primeira vez
DOMException: "A mutation operation was attempted on a database that did not allow mutations." ConnectionFactory.js:45:29
InvalidStateError NegociacaoService.js:87:21
Quando tento adicionar uma negociação
DOMException: "A mutation operation was attempted on a database that did not allow mutations." ConnectionFactory.js:45:29
InvalidStateError NegociacaoService.js:74:21
Quando tento apagar
DOMException: "A mutation operation was attempted on a database that did not allow mutations."
InvalidStateError NegociacaoService.js:101:21
