code: func CreateAccount(h *Host, impl string) (*RunContext, error) {
  	imp, ok := h.imp[impl]
  	if !ok {
  		return nil, fmt.Errorf("host does not have a %v importer", impl)
  	}
  	ia, err := imp.newAccount()
  	if err != nil {
  		return nil, fmt.Errorf("could not create new account for importer %v: %v", impl, err)
  	}
  	rc := &RunContext{
  		Host: ia.im.host,
  		ia:   ia,
  	}
  	rc.ctx, rc.cancel = context.WithCancel(context.WithValue(context.Background(), ctxutil.HTTPClient, ia.im.host.HTTPClient()))
  	return rc, nil
  
  }
docs: // CreateAccount creates a new importer account for the Host h, and the importer
  // implementation named impl. It returns a RunContext setup with that account.