presto-hive/src/main/java/io/prestosql/plugin/hive/rcfile/RcFilePageSource.java/RcFilePageSource/close
class RcFilePageSource:    @Override
    public void close()
            throws IOException
    {
        // some hive input formats are broken and bad things can happen if you close them multiple times
        if (closed) {
            return;
        }
        closed = true;

        rcFileReader.close();
    }