Hi, I am not sure how to report HARPTA Withholding shown on my Settlement Statement for a property sold in 2017. Is it a valid selling expense? Where do I capture it?

I understand HARPTA is not a tax (merely an estimate of HI income taxes that might be due following a sale of property), so, presumably, I may not include it as other taxes paid in my itemized federal return, or am I wrong?

It seems the simplest thing would be to include it as a selling expense in connection with the property sale (a condo in this case).  Most other expenses that reduced the proceeds I received from the sale count as valid selling expenses, but does HARPTA withholding also count?  If not, where do I report the HARPTA withholding in my federal return?

Thank you in advance.