docs: def upload(self, href, vobject_item):
          """Upload a new or replace an existing item."""
          if self.is_fake:
              return
  
          content = vobject_item.serialize()
          try:
              item = self.get(href)
              etesync_item = item.etesync_item
              etesync_item.content = content
          except api.exceptions.DoesNotExist:
              etesync_item = self.collection.get_content_class().create(self.collection, content)
  
          etesync_item.save()
  
          return self.get(href)