code: func vmReferences(vms []*object.VirtualMachine) []types.ManagedObjectReference {
  	refs := make([]types.ManagedObjectReference, len(vms))
  	for i, vm := range vms {
  		refs[i] = vm.Reference()
  	}
  	return refs
  }
docs: // this is annoying, but the likely use cases for Datacenter.PowerOnVM outside of this command would
  // use []types.ManagedObjectReference via ContainerView or field such as ResourcePool.Vm rather than the Finder.