code: func GetEngineVersions(ctx context.Context, registryClient registryclient.RegistryClient, registryPrefix, imageName, versionString string) (clitypes.AvailableVersions, error) {
  
  	if imageName == "" {
  		var err error
  		localMetadata, err := GetCurrentRuntimeMetadata("")
  		if err != nil {
  			return clitypes.AvailableVersions{}, err
  		}
  		imageName = localMetadata.EngineImage
  	}
  	imageRef, err := reference.ParseNormalizedNamed(path.Join(registryPrefix, imageName))
  	if err != nil {
  		return clitypes.AvailableVersions{}, err
  	}
  
  	tags, err := registryClient.GetTags(ctx, imageRef)
  	if err != nil {
  		return clitypes.AvailableVersions{}, err
  	}
  
  	return parseTags(tags, versionString)
  }
docs: // GetEngineVersions reports the versions of the engine that are available