public void LoadAssembly()
{
    Assemblies = null;
    AssemblyService.GetAssemblies(GetAssembliesCallback);
}
private void GetAssembliesCallback(ObservableCollection<TSMVVM.Model.Assemblies> assemblies)
{
    if (assemblies != null)
    {
        this.Assemblies = assemblies;
    }
}