docs: def get_milestone(self, title):
          """
          given the title as str, looks for an existing milestone or create a new one,
          and return the object
          """
          if not title:
              return GithubObject.NotSet
          if not hasattr(self, '_milestones'):
              self._milestones = {m.title: m for m in self.repo.get_milestones()}
  
          milestone = self._milestones.get(title)
          if not milestone:
              milestone = self.repo.create_milestone(title=title)
          return milestone