code: def attempt_colab_login(app_url):
      """This renders an iframe to wandb in the hopes it posts back an api key."""
      from google.colab import output
      from google.colab._message import MessageError
      from IPython import display
  
      display.display(
          display.Javascript(
              """
          window._wandbApiKey = new Promise((resolve, reject) => {
              function loadScript(url) {
              return new Promise(function(resolve, reject) {
                  let newScript = document.createElement("script");
                  newScript.onerror = reject;
                  newScript.onload = resolve;
                  document.body.appendChild(newScript);
                  newScript.src = url;
              });
              }
              loadScript("https://cdn.jsdelivr.net/npm/postmate/build/postmate.min.js").then(() => {
              const iframe = document.createElement('iframe')
              iframe.style.cssText = "width:0;height:0;border:none"
              document.body.appendChild(iframe)
              const handshake = new Postmate({
                  container: iframe,
                  url: '%s/authorize'
              });
              const timeout = setTimeout(() => reject("Couldn't auto authenticate"), 5000)
              handshake.then(function(child) {
                  child.on('authorize', data => {
                      clearTimeout(timeout)
                      resolve(data)
                  });
              });
              })
          });
      """
              % app_url.replace("http:", "https:")
          )
      )
      try:
          return output.eval_js("_wandbApiKey")
      except MessageError:
          return None
  
imports: import json
  import logging
  import os
  import re
  import shutil
  import sys
  from base64 import b64encode
  from typing import Dict
  import requests
  from requests.compat import urljoin
  import wandb
  import wandb.util
  from wandb.sdk.lib import filesystem
label_desc: Use image node_id 8 for calling a global function with example usage: attempt_colab_login(app_url) and returns: output, None