code: def access_labels(self):
          
          access_labels = []
          for referrer in self.referrers:
              referrer_labels = [key for key, val in self.root.labels.items()
                                 if val == referrer]
              port_labels = [key for key, val in referrer.labels.items()
                             if val == self]
              if referrer is self.root:
                  for label in port_labels:
                      access_labels.append("['{}']".format(label))
              for label in itertools.product(referrer_labels, port_labels):
                  access_labels.append("['{}']".format("']['".join(label)))
  
          return access_labels
docs: List of labels used to access the Port
  
          Returns
          -------
          list of str
              Strings that can be used to access this Port relative to self.root