def zero.sum
import bend-kit-tar@0.3.0.0/tar.bend as Tarimport Base
import bend-kit-bytes@0.3.3.0/bytes.bend as Bytes
370def zero.sum(+len: U32, r: Array<U32> & U32) -> Bytes.Bytes & Maybe<&2, U32>:
371 (a, sum) = r
372 (Bytes.Bytes{len, a}, Some{sum})