code: def attach_cluster(url):
      
      with shakedown.stdchannel_redirected(sys.stderr, os.devnull):
          clusters = [c.dict() for c in dcos.cluster.get_clusters()]
      for c in clusters:
          if url == c['url']:
              try:
                  dcos.cluster.set_attached(dcos.cluster.get_cluster(c['name']).get_cluster_path())
                  return True
              except:
                  return False
  
      return False
docs: Attach to an already set-up cluster
      :return: True if successful, else False