presto-example-http/src/main/java/io/prestosql/plugin/example/ExampleRecordCursor.java/ExampleRecordCursor/advanceNextPosition
class ExampleRecordCursor:    @Override
    public boolean advanceNextPosition()
    {
        if (!lines.hasNext()) {
            return false;
        }
        String line = lines.next();
        fields = LINE_SPLITTER.splitToList(line);

        return true;
    }