public void getNamespace(Context ctx) {
    handleNamespace(
        ctx,
        (catalog, database) ->
            GetNamespaceResponse.builder().withNamespace(Namespace.of(database)).build());
  }
GET PREFIX/v1/catalogs/{catalog}/namespaces/{namespaces}
amoro-ams/src/main/java/org/apache/amoro/server/RestCatalogService.java