code: func (a *Agent) ForceLeave(node string) (err error) {
  	a.logger.Printf("[INFO] agent: Force leaving node: %v", node)
  	err = a.delegate.RemoveFailedNode(node)
  	if err != nil {
  		a.logger.Printf("[WARN] agent: Failed to remove node: %v", err)
  	}
  	return err
  }
docs: // ForceLeave is used to remove a failed node from the cluster