def init_app(self, app,<EOL>entry_point_group='<STR_LIT>', **kwargs):
self.init_config(app)<EOL>state = _RecordsState(app, entry_point_group=entry_point_group)<EOL>app.extensions['<STR_LIT>'] = state<EOL>return state<EOL>
Flask application initialization.

        :param app: The Flask application.
        :param entry_point_group: The entrypoint for jsonresolver extensions.
            (Default: ``'invenio_records.jsonresolver'``)