@Override
  public String getName() {
    if (_distinctResult == 1) {
      return TransformFunctionType.IS_DISTINCT_FROM.getName();
    }
    return TransformFunctionType.IS_NOT_DISTINCT_FROM.getName();
  }
@Test
  public void testDistinctFromLeftFunctionRightIdentifier()
      throws Exception {
    ExpressionContext expression =
        RequestContextUtils.getExpression(String.format(_expression, "NULL + 1", INT_SV_NULL_COLUMN));
    TransformFunction transformFunction = TransformFunctionFactory.get(expression, _dataSourceMap);
    Assert.assertEquals(transformFunction.getName(), _isDistinctFrom ? "is_distinct_from" : "is_not_distinct_from");
    boolean[] expectedIntValues = new boolean[NUM_ROWS];
    for (int i = 0; i < NUM_ROWS; i++) {
      if (isNullRow(i)) {
        expectedIntValues[i] = !_isDistinctFrom;
      } else {
        expectedIntValues[i] = _isDistinctFrom;
      }
    }

    testTransformFunction(expression, expectedIntValues, _projectionBlock, _dataSourceMap);
  }