Function instantiate_network 

pub(crate) async fn instantiate_network(
    context: &Context,
    signing_key: PrivateKey,
    listen_addr: SocketAddr,
    mailbox_size: usize,
    max_message_size: usize,
    allow_unregistered_handshakes: bool,
) -> Result<(Network<Context, PrivateKey>, Oracle<PublicKey>)>