def expand
import bend-collections@1.0.0.0/src/crypto/kdf.bend as Kdfimport Base
46def expand(+prk: List<&2, U32>, +info: List<&2, U32>, +len: Nat) -> Result<&2, &2, KdfError, List<&2, U32>>:
47 expand_if(prk, info, len, Nat.is_le(len, max_length()))