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