#vulnerable code 
                                @Test
    public void testMutators() {
        final CSVFormat format = new CSVFormat('!', '!', null, '!', '!', true, true, CRLF, null);

        assertEquals('?', format.withDelimiter('?').getDelimiter());
        assertEquals('?', format.withEncapsulator('?').getEncapsulator().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
#fixed 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());
    }