@Override
  public String getName() {
    return _name;
  }
@Test
  public void testIsNullOperator() {
    ExpressionContext expression =
        RequestContextUtils.getExpression(String.format("%s IS NULL", BIG_DECIMAL_SV_COLUMN));
    TransformFunction transformFunction = TransformFunctionFactory.get(expression, _dataSourceMap);
    assertTrue(transformFunction instanceof IsNullTransformFunction);
    assertEquals(transformFunction.getName(), "is_null");
    int[] expectedValues = new int[NUM_ROWS];
    for (int i = 0; i < NUM_ROWS; i++) {
      expectedValues[i] = (_bigDecimalSVValues[i] == null) ? 1 : 0;
    }
    testTransformFunction(transformFunction, expectedValues);
  }