pub fn send_async<'s, 'r>(
            &'s mut self,
            dst_addr: &'r [u8; 6],
            data: &'r [u8],
        ) -> SendFuture<'s, 'r> {
            self.sender.send_async(dst_addr, data)
        }
The returned future must not be dropped before it's ready to avoid
getting wrong status for sendings.
esp-wifi/src/esp_now/mod.rs