public void OnTypeCreation(MetadataContainer metadataContainer)
 {
     metadataContainer.Entity <Foo>().Projection(x => x.Id2).IsKey();
     metadataContainer.Add(new FooMetadata());
     metadataContainer.Entity <Bar>().Projection(x => x.FooSet).Association().WithName("MyAssociation").
     WithThisKey(x => x.Id2, x => x.Id).WithOtherKey(x => x.Id2, x => x.Id);
 }