code: func (m *Manager) StartCustomProvider(ctx context.Context, name string, worker Discoverer) {
  	p := &provider{
  		name: name,
  		d:    worker,
  		subs: []string{name},
  	}
  	m.providers = append(m.providers, p)
  	m.startProvider(ctx, p)
  }
docs: // StartCustomProvider is used for sdtool. Only use this if you know what you're doing.