@Override
    public void init(Context context) {
      TranslatorContext translatorContext =
          ((SamzaSqlApplicationContext) context.getApplicationTaskContext()).getTranslatorContexts().get(queryId);
      relConverter = translatorContext.getMsgConverter(source);
    }
Translator to translate the TableScans in relational graph to the corresponding input streams in the StreamGraph
implementation
samza-sql/src/main/java/org/apache/samza/sql/translator/ScanTranslator.java