panic(err.Error())
	}
}

// Trace represents an execution trace for testing.
//
// It does a little bit of work to ensure that the produced trace is valid,
// just for convenience. It mainly tracks batches and batch sizes (so they're
// trivially correct), tracks strings and stacks, and makes sure emitted string
// and stack batches are valid. That last part can be controlled by a few options.
//