/// <summary>
/// Obtains an instance of <typeparamref name="T"/> from the factory
/// class specified in <see cref="FactoryType"/>.
/// </summary>
/// <returns>An instance of <typeparamref name="T"/>.</returns>
public T ObtainInstance()
{
if (_factory == null)
{
throw new ApplicationException("Factory not specified");
}
return(_factory.ObtainInstance());
}