Hi there,
thanks for the nice crate 👍
I was trying out Supervisors though and I don't quite understand how to use them. I seem to always get a panic inside of futures-channels mpcs code when I launch one.

here is a minimal example

use xactor::Actor;

pub struct ServiceA {
    pub session_id: u32,
}

#[async_trait::async_trait]
impl Actor for ServiceA { }

#[async_std::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    xactor::Supervisor::start(|| ServiceA { session_id: 4 }).await?;

    Ok(())
}

this causes a panic with the following messages for me

thread 'async-std/runtime' panicked at 'Receiver::next_message called after `None`', /home/hoodie/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-channel-0.3.5/src/mpsc/mod.rs:1141:41

do you have any idea what could be the reason for this?

thank you