Major Description
When creating a org.apache.commons.vfs2.impl.VirtualFileSystem by org.apache.commons.vfs2.impl.VirtualFileProvider it is tracked as a component. But since VirtualFileProvider is not an AbstractFileProvider and not registered in providers it will never be closed by org.apache.commons.vfs2.impl.DefaultFileSystemManager._closeFileSystem(FileSystem). Also the final instance of VirtualFileProvider does not get closed when the DefaultFileSystemManager gets closed.
VirtualFileSystem itself does not have critical resources, but its DelegatedFiles are cached so there should be a way to close them.