You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: service.rs
    path of file: ./repos/vector/src/sinks/amqp
    
    the code of the file until where you have to start completion: //! The main tower service that takes the request created b
    
    fn call(&mut self, req: AmqpRequest) -> Self::Future {
        let channel = Arc::clone(&self.channel);

        Box::pin(async move {
            let byte_size = req.body.len();
            let fut = channel
                .basic_publish(
                    &req.exchange,
                    &req.routing_key,
                    BasicPublishOptions::default(),
                    req.body.as_ref(),
                    req.properties,
                )
                .await;

            match fut {
                Ok(result) => match result.await {
                    Ok(lapin::publisher_confirm::Confirmation::Nack(_)) => Err(AmqpError::Nack),
                    Err(error) => Err(AmqpError::AcknowledgementFailed { error }),
                    Ok(_) => Ok(AmqpResponse {
                        json_size: req.metadata.into_events_estimated_json_encoded_byte_size(),
                        byte_size,
                    }),
                },
                Err(error) => Err(AmqpError::DeliveryFailed { error }),
            }
        })
    }