presto-main/src/main/java/io/prestosql/split/SplitManager.java/SplitManager/getConnectorSplitManager
class SplitManager:    private ConnectorSplitManager getConnectorSplitManager(CatalogName catalogName)
    {
        ConnectorSplitManager result = splitManagers.get(catalogName);
        checkArgument(result != null, "No split manager for connector '%s'", catalogName);
        return result;
    }