presto-main/src/main/java/io/prestosql/operator/ExchangeOperator.java/ExchangeOperator/addSplit
class ExchangeOperator:    @Override
    public Supplier<Optional<UpdatablePageSource>> addSplit(Split split)
    {
        requireNonNull(split, "split is null");
        checkArgument(split.getCatalogName().equals(REMOTE_CONNECTOR_ID), "split is not a remote split");

        URI location = ((RemoteSplit) split.getConnectorSplit()).getLocation();
        exchangeClient.addLocation(location);

        return Optional::empty;
    }