### Question:
GraphStoreCatalog { public static void set(GraphCreateConfig config, GraphStore graphStore) { graphStore.canRelease(false); userCatalogs.compute(config.username(), (user, userCatalog) -> { if (userCatalog == null) { userCatalog = new UserCatalog(); } userCatalog.set( UserCatalog.UserCatalogKey.of(graphStore.databaseId(), config.graphName()), config, graphStore ); return userCatalog; }); } private  GraphStoreCatalog(); static GraphStoreWithConfig get(String username, NamedDatabaseId databaseId, String graphName); static void set(GraphCreateConfig config, GraphStore graphStore); static Optional<Graph> getUnion(String username, NamedDatabaseId databaseId, String graphName); static boolean exists(String username, NamedDatabaseId databaseId, String graphName); static void remove(
        String username,
        NamedDatabaseId databaseId,
        String graphName,
        Consumer<GraphStoreWithConfig> removedGraphConsumer,
        boolean failOnMissing
    ); static int graphStoresCount(); static int graphStoresCount(NamedDatabaseId databaseId); static Optional<Map<String, Object>> getDegreeDistribution(String username, NamedDatabaseId databaseId, String graphName); static void setDegreeDistribution(String username, NamedDatabaseId databaseId, String graphName, Map<String, Object> degreeDistribution); static void removeAllLoadedGraphs(); static Map<GraphCreateConfig, GraphStore> getGraphStores(String username); static Map<GraphCreateConfig, GraphStore> getGraphStores(String username, NamedDatabaseId databaseId);  }### Answer:
@Test void set() { assertFalse(GraphStoreCatalog.exists(USER_NAME, DATABASE_ID, GRAPH_NAME)); GraphStoreCatalog.set(CONFIG, graphStore); assertTrue(GraphStoreCatalog.exists(USER_NAME, DATABASE_ID, GRAPH_NAME)); }