pub fn tcp_keepalive(self, tcp_keepalive: Option<Duration>) -> Self {
        Endpoint {
            tcp_keepalive,
            ..self
        }
    }
Set whether TCP keepalive messages are enabled on accepted connections.

If `None` is specified, keepalive is disabled, otherwise the duration
specified will be the time to remain idle before sending TCP keepalive
probes.

Default is no keepalive (`None`)
tonic/src/transport/channel/endpoint.rs