code: func (m *Module) SvcHost() (svchost.Hostname, error) {
  	if m.RawHost == nil {
  		return svchost.ForComparison(PublicRegistryHost.Raw)
  	}
  	return svchost.ForComparison(m.RawHost.Raw)
  }
docs: // SvcHost returns the svchost.Hostname for this module. Since FriendlyHost may
  // contain an invalid hostname, this also returns an error indicating if it
  // could be converted to a svchost.Hostname. If no host is specified, the
  // default PublicRegistryHost is returned.