code: def get(self, id):
          
          collection_name = self.request.headers.get("collection")
  
          if not collection_name:
              self.raise_error(400, "Missing a collection name for stack")
  
          self.stack = AsyncSchedulableDocumentRevisionStack(collection_name, self.settings)
  
          revision = yield self.stack.preview(id)
          self.write(revision)
docs: Get revision based on the stack preview algorithm
  
          :param id: BSON id
          :return: JSON