public IVsPackage LoadPackage(Guid packageGuid)
{
IVsShell shellService = (IVsShell)VsIdeTestHostContext.ServiceProvider.GetService(typeof(SVsShell));
IVsPackage package;
shellService.LoadPackage(ref packageGuid, out package);
Assert.IsNotNull(package, "Failed to load package");
return package;
}