Such determination and order of the court of common pleas shall not be subject to any other appeal or review, or to collateral attack of any kind whatsoever, but shall, with respect to the validity of all municipal loans, and in all other respects, be final and conclusive; and the proceeding herein provided for shall be the sole and exclusive method of determining the aforesaid matters relating to the amount of the debt of the city of Philadelphia which may be deducted from its indebtedness, in ascertaining its borrowing capacity, by reason of such debt having been incurred and the proceeds thereof invested in any public improvements of any character which shall be yielding to the said city an annual current net revenue.
53 P.S. § 16993