def METHOD_NAME(self):
    _content_value, _builder = self.new_content_builder(
        self.ctx.args,
        typ=AAZObjectType,
        typ_kwargs={"flags": {"client_flatten": True}}
    )
    _builder.set_prop("instanceIds", AAZListType, ".instance_ids")
    instance_ids = _builder.get(".instanceIds")
    if instance_ids is not None:
        instance_ids.set_elements(AAZStrType, ".")
    return self.serialize_content(_content_value)