pub unsafe extern "C" fn flatpak_installation_fetch_remote_size_sync(
self_: *mut FlatpakInstallation,
remote_name: *const c_char,
ref_: *mut FlatpakRef,
download_size: *mut u64,
installed_size: *mut u64,
cancellable: *mut GCancellable,
error: *mut *mut GError
) -> gboolean