code: def record_changeset(self, custom_changeset_id: uuid.UUID = None) -> uuid.UUID:
          
          if custom_changeset_id is not None:
              if custom_changeset_id in self.journal_data:
                  raise ValidationError(
                      "Tried to record with an existing changeset id: %r" % custom_changeset_id
                  )
              else:
                  changeset_id = custom_changeset_id
          else:
              changeset_id = uuid.uuid4()
  
          self.journal_data[changeset_id] = {}
          return changeset_id
docs: Creates a new changeset. Changesets are referenced by a random uuid4
          to prevent collisions between multiple changesets.