tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/engine/function/string/Left.java [48:79]:
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    super(new Column[] {
        new Column("string", TajoDataTypes.Type.TEXT),
        new Column("size", TajoDataTypes.Type.INT4)
    });
  }

  public int getSize(int length, int size) {
    if (size < 0) {
        size = length + size;
        if (size < 0) {
            size = 0;
        }
    }

    return (size < length) ? size : length;
  }

  @Override
  public Datum eval(Tuple params) {
    Datum datum = params.get(0);
    if(datum instanceof NullDatum) return NullDatum.get();

    Datum sizeDatum = params.get(1);
    if(sizeDatum instanceof NullDatum) return NullDatum.get();

    String data = datum.asChars();
    int length = data.length();
    int size = sizeDatum.asInt4();

    size = getSize(length, size);
    if (size == 0) {
        return TextDatum.EMPTY_TEXT;
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tajo-core/tajo-core-backend/src/main/java/org/apache/tajo/engine/function/string/Right.java [48:79]:
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    super(new Column[] {
        new Column("string", TajoDataTypes.Type.TEXT),
        new Column("size", TajoDataTypes.Type.INT4)
    });
  }

  public int getSize(int length, int size) {
    if (size < 0) {
        size = length + size;
        if (size < 0) {
            size = 0;
        }
    }

    return (size < length) ? size : length;
  }

  @Override
  public Datum eval(Tuple params) {
    Datum datum = params.get(0);
    if(datum instanceof NullDatum) return NullDatum.get();

    Datum sizeDatum = params.get(1);
    if(sizeDatum instanceof NullDatum) return NullDatum.get();

    String data = datum.asChars();
    int length = data.length();
    int size = sizeDatum.asInt4();

    size = getSize(length, size);
    if (size == 0) {
        return TextDatum.EMPTY_TEXT;
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