code: func (a *Agent) purgeCheckState(checkID types.CheckID) error {
  	file := filepath.Join(a.config.DataDir, checkStateDir, checkIDHash(checkID))
  	err := os.Remove(file)
  	if os.IsNotExist(err) {
  		return nil
  	}
  	return err
  }
docs: // purgeCheckState is used to purge the state of a check from the data dir