code: def tracking_branch(self):
          
          from .remote import RemoteReference
          reader = self.config_reader()
          if reader.has_option(self.k_config_remote) and reader.has_option(self.k_config_remote_ref):
              ref = Head(self.repo, Head.to_full_path(strip_quotes(reader.get_value(self.k_config_remote_ref))))
              remote_refpath = RemoteReference.to_full_path(join_path(reader.get_value(self.k_config_remote), ref.name))
              return RemoteReference(self.repo, remote_refpath)
          # END handle have tracking branch
  
          # we are not a tracking branch
          return None
docs: :return: The remote_reference we are tracking, or None if we are
              not a tracking branch