Make a column unique powershell CSOM

Question

How can I Enforce unique values: in powershell? Client-side as well not server-side Here is the code that I have :

$ListInfo = New-Object Microsoft.SharePoint.Client.ListCreationInformation
$ListInfo.Title = $ListTitle
$ListInfo.TemplateType = "100"
$myList = $web.Lists.Add($ListInfo)
$myList.Description = $ListTitle
$myList.Update()
$Fields=$myList.Fields
$ctx.Load($Fields)
$ctx.ExecuteQuery() 
$myList.Fields.AddFieldAsXml("<Field Type='Number' DisplayName='SortOrder' />",$true,[Microsoft.SharePoint.Client.AddFieldOptions]::AddFieldToDefaultView)

$myList.Update()
$ctx.ExecuteQuery()

just need to make it a unique field

Answer 1

http://msdn.microsoft.com/en-us/library/office/ee536168%28v=office.14%29.aspx

Here is a link that should help you better understand what you need to do. I suppose just writing

$Fields.Indexed = true;
$Fields.EnforceUniqueValues = true; 

would suffice. I haven't worked with this, but the example seems like you have to do this on a list object, not a listcollection object.

EDIT: It seems, to this day, I cannot tell the difference between Acronym's (even had to look that word up to remember it). This answer applies to SSOM and not CSOM. Please see comments for more information.

$fieldname.indexed = $true; 
$fieldname.EnforcedUniqueValues = $true
$fieldname.Update()

Thanks to bimbob for supplying the CSOM equivilant.