pub type U8 = UInt<UInt<UInt<UInt<UTerm, B1>, B0>, B0>, B0>;
struct U8 { pub(crate) msb: UInt<UInt<UInt<UTerm, B1>, B0>, B0>, pub(crate) lsb: B0, }
msb: UInt<UInt<UInt<UTerm, B1>, B0>, B0>
lsb: B0