if _, err := f.WriteString(tc.initialFileContents); err != nil {
				t.Fatalf("Failed to write to file: %v", err)
			}
			f.Close()
			args := fmt.Sprintf("source configure-helper.sh; append_or_replace_prefixed_line %s %s %s", f.Name(), tc.prefix, tc.suffix)
			cmd := exec.Command("bash", "-c", args)
			stderr, err := cmd.CombinedOutput()
			if err != nil {
				t.Fatalf("Failed to run command: %v: %s", err, stderr)
			}

    append_or_replace_prefixed_line "${known_tokens_csv}" "${KUBE_SCHEDULER_TOKEN},"          "system:kube-scheduler,uid:system:kube-scheduler"
  fi
  if [[ -n "${KUBE_CLUSTER_AUTOSCALER_TOKEN:-}" ]]; then
    append_or_replace_prefixed_line "${known_tokens_csv}" "${KUBE_CLUSTER_AUTOSCALER_TOKEN}," "cluster-autoscaler,uid:cluster-autoscaler"
  fi
  if [[ -n "${KUBE_PROXY_TOKEN:-}" ]]; then