/**
  * not supported because is not a valid version.
  *
  * @throws Exception if occur
  */
 @Test
 public void supports_invalid_version() throws Exception {
   ExcelRuleExtractor extractor = new DefaultExcelRuleExtractor();
   Sheet sheet = sheet("invalid_format_version.xls");
   assertThat(extractor.supports(sheet), is(false));
 }
 /**
  * using xlsx.
  *
  * @throws Exception if occur
  */
 @Test
 public void xssf() throws Exception {
   ExcelRuleExtractor extractor = new DefaultExcelRuleExtractor();
   Sheet sheet = sheet("simple.xlsx");
   assertThat(extractor.supports(sheet), is(true));
 }