Error: The argument type 'Transferencia?' can't be assigned to the parameter type 'Transferencia' because 'Transferencia?' is nullable and 'Transferencia' isn't.
Error: The argument type 'Transferencia?' can't be assigned to the parameter type 'Transferencia' because 'Transferencia?' is nullable and 'Transferencia' isn't.
Torne a listaTransferencia não nullable:
final List<Transferencia> _transferencias = [];