output: #fixed code
                                  @Test
      public void testMutators() {
          final CSVFormat format = new CSVFormat('!', '!', null, '!', '!', true, true, CRLF, null);
  
          assertEquals('?', format.withDelimiter('?').getDelimiter());
          assertEquals('?', format.withQuoteChar('?').getQuoteChar().charValue());
          assertEquals('?', format.withCommentStart('?').getCommentStart().charValue());
          assertEquals("?", format.withLineSeparator("?").getLineSeparator());
          assertEquals('?', format.withEscape('?').getEscape().charValue());
  
          assertFalse(format.withIgnoreSurroundingSpaces(false).getIgnoreSurroundingSpaces());
          assertFalse(format.withIgnoreEmptyLines(false).getIgnoreEmptyLines());
  
          assertEquals(Quote.ALL, format.withQuotePolicy(Quote.ALL).getQuotePolicy());
      }
input: #vulnerable code 
                                  @Test
      public void testMutators() {
          final CSVFormat format = new CSVFormat('!', '!', null, '!', '!', true, true, CRLF, null);
  
          assertEquals('?', format.withDelimiter('?').getDelimiter());
          assertEquals('?', format.withEncapsulator('?').getQuoteChar().charValue());
          assertEquals('?', format.withCommentStart('?').getCommentStart().charValue());
          assertEquals("?", format.withLineSeparator("?").getLineSeparator());
          assertEquals('?', format.withEscape('?').getEscape().charValue());
  
          assertFalse(format.withIgnoreSurroundingSpaces(false).getIgnoreSurroundingSpaces());
          assertFalse(format.withIgnoreEmptyLines(false).getIgnoreEmptyLines());
  
          assertEquals(Quote.ALL, format.withQuotePolicy(Quote.ALL).getQuotePolicy());
      } 
                              #location 6 
                              #vulnerability type NULL_DEREFERENCE