You can use code like that in `NginxSshDriver` for downloading add-ons:

`DownloadResolver pluginResolver = entity.getManagementContext().getEntityDownloadsManager().newDownloader(this, "w3TotalCache", ImmutableMap.of("addonversion", w3TotalCacheVersion));`

And in Wordpress interface:

    `@SetFromFlag("downloadAddonUrls")`
    `BasicAttributeSensorAndConfigKey<Map<String,String>> DOWNLOAD_ADDON_URLS = new 
    `BasicAttributeSensorAndConfigKey<Map<String,String>>(SoftwareProcess.DOWNLOAD_ADDON_URLS, 
    `ImmutableMap.of("w3TotalCache", "http://downloads.wordpress.org/plugin/w3-total-cache${addonversion}.zip"));`

Suggested improvements to that code greatly appreciated!