Neb. Rev. Stat. § 14-513

The city comptroller of a city of the metropolitan class shall deduct from the amount of any credit or warrant all amounts which the payee may owe the city, and where there has been an assignment of such credit or warrant the city comptroller shall likewise deduct as well all amounts which the assignee may owe the city. Should the amounts owing exceed the amount of the warrant, the amounts thus deducted shall be credited pro tanto on the obligations owing the city. An assignment of the claim shall not defeat the right of the city to deduct the amount of the debt from the amount due the claimant. The claimant or the claimant's assignee may appeal from the action of the city comptroller in so deducting any amount from the claim in the manner provided for appeals in section 14-813 .