def METHOD_NAME(self):
    template_filename = 'template.json'
    with TemporaryDirectory() as tmp:
        tmpl = '{}'
        pathname = os.path.join(tmp, template_filename)
        with open(pathname, 'w') as f:
            f.write(tmpl)
        data = {"template": template_filename, "extra_paths": [tmp]}
        exporter_unit = mock.Mock(spec=ExporterUnitSupport, data=data)
        exporter_unit.file_extension = 'json'
        exporter_unit.data_dir = tmp
        exporter_unit.template = template_filename
        exporter_unit.option_list = ()
        exporter = Jinja2SessionStateExporter(exporter_unit=exporter_unit)
        exporter.validate_json = mock.Mock(return_value=[])
        stream = BytesIO()
        exporter.validate(stream)
        exporter.validate_json.assert_called_once_with(stream)