presto-example-http/src/main/java/io/prestosql/plugin/example/ExampleClient.java/ExampleClient/schemasSupplier
class ExampleClient:    private static Supplier<Map<String, Map<String, ExampleTable>>> schemasSupplier(final JsonCodec<Map<String, List<ExampleTable>>> catalogCodec, final URI metadataUri)
    {
        return () -> {
            try {
                return lookupSchemas(metadataUri, catalogCodec);
            }
            catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        };
    }