* ````
fn consume<R, F>(mut self, f: F) -> R
        where F: FnOnce(&mut [u8]) -> R
    {
        // TODO: receive packet into buffer
        let result = f(&mut self.0);
        println!("rx called");
        result
    }
````
Is this meant to be blocking? That seems like it would prevent the `poll()` from returning, but I'm not sure how to report no packet available