code: func checkerNames(checks ...HealthzChecker) []string {
  	// accumulate the names of checks for printing them out.
  	checkerNames := make([]string, 0, len(checks))
  	for _, check := range checks {
  		checkerNames = append(checkerNames, check.Name())
  	}
  	return checkerNames
  }
docs: // checkerNames returns the names of the checks in the same order as passed in.