DocumentExist Response on .NET low level client

I am trying to check a document exist or not using the following code:

Me.LowLevelClient.DocumentExists(Of Elasticsearch.Net.StringResponse)(index:=TargetIndexName,

But it returns with Body prop empty (it's a successful call (200)).
Maybe I did it wrong?
Thank you in advanced for your help.

Turned out I have to use the:

Me.LowLevelClient.DocumentExists uses HEAD, which is not what I want.