New Post: Use MEF to allow only 2 instances at max per application

I am using MEF as an IOC in my application. I found myself stuck in a situation where I need exactly two instance at a time for a class in my application (across all threads). I thought it would be easy just by adding export attribute twice with different container name and then using that container name to create two instances.

[Export("Condition-1",typeof(MyClass)]
[Export("Condition-2",typeof(MyClass)]
[PartCreationPolicy(System.ComponentModel.Composition.CreationPolicy.Shared)]
public class MyClass  {   }

And then get export as

Container.GetExport<MyClass>("Condition-1").Value
Container.GetExport<MyClass>("Condition-2").Value

But this trick did not work. CreationPolicy is ignoring the ContractName and is returning one instance no matter what contract name i use in GetExport. I finally able to solve my problem by using CompsositionBatch

cb.AddExportedValue<MyClass>("Condition-1",new MyClass());
cb.AddExportedValue<MyClass>("Condition-2",new MyClass());

But my question is, Why am I not able to get different instances on the basis of Contract Name. Is it right that Contract name does not matter if CreationPolicy is shared?