/** @throws Exception if occur */
 @Test
 public void extractNullityCondition() throws Exception {
   ExcelRuleExtractor extractor = new DefaultExcelRuleExtractor();
   Sheet sheet = sheet("nullity.xls");
   assertThat(extractor.extractNullityCondition(sheet.getRow(3)), is(NullityConditionKind.NORMAL));
   assertThat(
       extractor.extractNullityCondition(sheet.getRow(4)), is(NullityConditionKind.ACCEPT_ABSENT));
   assertThat(
       extractor.extractNullityCondition(sheet.getRow(5)), is(NullityConditionKind.DENY_ABSENT));
   assertThat(
       extractor.extractNullityCondition(sheet.getRow(6)),
       is(NullityConditionKind.ACCEPT_PRESENT));
   assertThat(
       extractor.extractNullityCondition(sheet.getRow(7)), is(NullityConditionKind.DENY_PRESENT));
 }
 /**
  * nullity - invalid cell.
  *
  * @throws Exception if occur
  */
 @Test(expected = ExcelRuleExtractor.FormatException.class)
 public void extractNullityCondition_invalid() throws Exception {
   ExcelRuleExtractor extractor = new DefaultExcelRuleExtractor();
   Sheet sheet = sheet("nullity.xls");
   extractor.extractNullityCondition(sheet.getRow(11));
 }