private void ApplyOptions()
{
_errorTrace = DafnyOptions.O.ErrorTrace;
DafnyOptions.O.ErrorTrace = 0;
_verifySnapshots = DafnyOptions.O.VerifySnapshots;
DafnyOptions.O.VerifySnapshots = 1;
_printer = Bpl.ExecutionEngine.printer;
Bpl.ExecutionEngine.printer = new InvisibleConsolePrinter();
Contract.ContractFailed += ContractFailureHandler;
}