code: func (c *Controller) WorkerInfos() []client.WorkerInfo {
  	workers, err := c.List()
  	if err != nil {
  		return nil
  	}
  	out := make([]client.WorkerInfo, 0, len(workers))
  	for _, w := range workers {
  		out = append(out, client.WorkerInfo{
  			ID:        w.ID(),
  			Labels:    w.Labels(),
  			Platforms: w.Platforms(),
  		})
  	}
  	return out
  }
docs: // TODO: add Get(Constraint) (*Worker, error)