in fastpay/src/transport.rs [175:184]
fn send_data_to<'a>(
&'a mut self,
buffer: &'a [u8],
address: &'a str,
) -> future::BoxFuture<'a, Result<(), std::io::Error>> {
Box::pin(async move {
self.socket.send_to(buffer, address).await?;
Ok(())
})
}