How can I get disk-limit immediately after quota-resize?

SDK : netapp-manageability-sdk-5.4P1    powershell

SAMPLE -----

[NetApp.Manage.NaElement] $in =  New-Object NetApp.Manage.NaElement("quota-resize");
$in.AddNewChild("volume",$volume);
[NetApp.Manage.NaElement] $out = $s.InvokeElem($in);

[NetApp.Manage.NaElement] $in =  New-Object NetApp.Manage.NaElement("quota-report-iter");
$in.AddNewChild("path",$path2q);
[NetApp.Manage.NaElement] $out = $s.InvokeElem($in);

[System.Collections.IList] $quotaList =  $out.GetChildByName("attributes-list").GetChildren();
[System.Collections.IEnumerator] $quotaIter = $quotaList.GetEnumerator();
while($quotaIter.MoveNext()){
   [NetApp.Manage.NaElement] $quotaInfo = $quotaIter.Current;
   $quotasize_ = $quotaInfo.GetChildContent("disk-limit");     ★
}

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★ this line dosent work.

if "sleep 1" above of line[$out.GetChildByName("attributes-list").GetChildren();]

it works.

Is there a way to avoid errors other than "sleep" ?

Best regards.