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: portforward.rs
    path of file: ./repos/kube/kube-client/src/api
    
    the code of the file until where you have to start completion: use std::{collections::HashMap, future::Future};

use bytes::{Buf, Bytes};
use futures::{
    channel::{mpsc, oneshot},
    future, Fut
    
    pub async fn join(self) -> Result<(), Error> {
        let Self {
            mut ports,
            mut errors,
            task,
        } = self;
        // Start by terminating any streams that have not yet been taken
        // since they would otherwise keep the connection open indefinitely
        ports.clear();
        errors.clear();
        task.await.unwrap_or_else(|e| Err(Error::Spawn(e)))
    }