def resolve_iou(pgt_iou)
      pstore = open_pstore

      pgt = nil
      pstore.transaction do
        pgt = pstore[pgt_iou]
        pstore.delete(pgt_iou) if pgt
      end

      pgt
    end
def resolve_iou(pgt_iou)
      pstore = open_pstore

      pgt = nil
      pstore.transaction do
        pgt = pstore[pgt_iou]
        pstore.delete(pgt_iou) if pgt
      end

      pgt
    end
Finds the PGT for the given PGTIOU.  If there isn't one, it
 returns nil.  If there is one, it deletes it from the store
 before returning it.

 @param [String] pgt_iou
 @return [String,nil]