Rest call to update 'Cores per socket' property of a VM

Team,

I am trying to automate the process of deploying VMs in Vcloud. One of the steps is to update VM properites(Memory,CPU etc.)

I am using a rest call to update Memory and CPU information. However, i am not able to update 'Cores per Socket' property using a rest call.

A very similar rest call is used in both cases but one property is updated and the other is not. what could be the reason? Is there any other way i could update the cores per socket property?

I would appreciate if anyone would help me in identifying the problem here.

Thanks,

Vinay.