Core class for fetching remote files and reading local files with SimplePie.

Constructor.

Whether a handle’s source is in a default directory.

Core class used for upgrading/installing a local set of files via the Filesystem Abstraction classes from a Zip file.

Construct the upgrader with a skin.

Download a package.

Connect to the filesystem.

Add the generic strings to WP_Upgrader::$strings.

Initialize the upgrader.

Install a package.