docs: def get_object(cls, bucket, key, version_id):
          """Retrieve object and abort if it doesn't exists.
  
          If the file is not found, the connection is aborted and the 404
          error is returned.
  
          :param bucket: The bucket (instance or id) to get the object from.
          :param key: The file key.
          :param version_id: The version ID.
          :returns: A :class:`invenio_files_rest.models.ObjectVersion` instance.
          """
          obj = ObjectVersion.get(bucket, key, version_id=version_id)
          if not obj:
              abort(404, 'Object does not exists.')
  
          cls.check_object_permission(obj)
  
          return obj