custom_tlvs.sort_unstable_by_key(|(typ, _)| *typ);
_encode_varint_length_prefixed_tlv!(w, {
(2, HighZeroBytesDroppedBigSize(*amt_msat), required),
custom_tlvs.sort_unstable_by_key(|(typ, _)| *typ);
_encode_varint_length_prefixed_tlv!(w, {
(2, HighZeroBytesDroppedBigSize(*amt_msat), required),