code: func (a *Agent) unloadChecks() error {
  	for id := range a.State.Checks() {
  		if err := a.removeCheckLocked(id, false); err != nil {
  			return fmt.Errorf("Failed deregistering check '%s': %s", id, err)
  		}
  	}
  	return nil
  }
docs: // unloadChecks will deregister all checks known to the local agent.