Creating a VM using the built-in "Create custom virtual machine" workflow with eager zero disk

How can I modify the built-in workflows to create a virtual disk that is eager zeroed?  The snippet to create the virtual disk looks like this:

if ( hasDisk1 == true )  {

    deviceConfigSpec = System.getModule("com.vmware.library.vc.vm.spec.config.device").createVirtualDiskFlatVer2ConfigSpec(

        disk1SizeInGB, vmDatastore, 0, 0, VcVirtualDiskMode.persistent, disk1ThinProvisioned );

    deviceConfigSpecs[ii++] = deviceConfigSpec;

The disk1ThinProvisioned gets set as answer to question during the set-up.  We want to set everything up as eager zeroed.  How can I change this snippet of code to accomplish that?

There is some information here about what needs to be done, but it's not specific enough for the uninitiated.