presto-atop/src/main/java/io/prestosql/plugin/atop/AtopPageSourceProvider.java/AtopPageSourceProvider/AtopPageSourceProvider
class AtopPageSourceProvider:    @Inject
    public AtopPageSourceProvider(AtopConnectorConfig config, AtopFactory atopFactory, TypeManager typeManager)
    {
        readerPermits = new Semaphore(requireNonNull(config, "config is null").getConcurrentReadersPerNode());
        this.atopFactory = requireNonNull(atopFactory, "atopFactory is null");
        this.typeManager = requireNonNull(typeManager, "typeManager is null");
    }