Handshake

/// Handles the handshake negotiation when two peers connect and decides on
/// protocol.
pub struct Handshake {
    /// Ring buffer of nonces sent to detect self connections without requiring
    /// a node id.
    nonces: Arc<RwLock<VecDeque<u64>>>,
    /// The genesis block header of the chain seen by this node.
    /// We only want to connect to other nodes seeing the same chain (forks are
    /// ok).
    genesis: Hash,
    config: P2PConfig,
}