/// <summary>
/// Extension mechanism for additional services;
/// </summary>
/// <returns>requested service provider or null.</returns>
object IServiceProvider.GetService(Type serviceType) {
object result = null;
if (serviceType == typeof(DbProviderServices)) {
result = EntityProviderServices.Instance;
}
else if (serviceType == typeof(IEntityAdapter)) {
result = new EntityAdapter();
}
return result;
}