pub enum RejectReason {
    /// malformed message
    MALFORMED = 0x01,
    /// invalid message
    INVALID = 0x10,
    /// obsolete message
    OBSOLETE = 0x11,
    /// duplicate message
    DUPLICATE = 0x12,
    /// nonstandard transaction
    NONSTANDARD = 0x40,
    /// an output is belw dust limit
    DUST = 0x41,
    /// insufficient fee
    FEE = 0x42,
    /// checkpoint
    CHECKPOINT = 0x43
}

fn main() {
    let a = RejectReason::CHECKPOINT;
    dbg!(a as u8);
}