#vulnerable code 
                                @Test
    public void testComposition() {

        CsvColumnDefinition compose = CsvColumnDefinition.compose(CsvColumnDefinition.compose(CsvColumnDefinition.dateFormatDefinition("yyyyMM"), CsvColumnDefinition.renameDefinition("blop")),
                CsvColumnDefinition.customReaderDefinition(new CellValueReader<Integer>() {
                    @Override
                    public Integer read(char[] chars, int offset, int length, ParsingContext parsingContext) {
                        return 3;
                    }
                }));

        assertEquals("blop", compose.rename(new CsvColumnKey("bar", -1)).getName());
        assertEquals("yyyyMM", compose.dateFormat());
        assertEquals(new Integer(3), compose.getCustomReader().read(null, 0, 0 , null));

        assertTrue(compose.hasCustomSource());
        assertEquals(Integer.class, compose.getCustomSourceReturnType());
    } 
                            #location 14 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testComposition() {

        CsvColumnDefinition compose = CsvColumnDefinition.dateFormatDefinition("yyyyMM").addRename("blop").addCustomReader(
                new CellValueReader<Integer>() {
                    @Override
                    public Integer read(char[] chars, int offset, int length, ParsingContext parsingContext) {
                        return 3;
                    }
                });

        assertEquals("blop", compose.rename(new CsvColumnKey("bar", -1)).getName());
        assertEquals("yyyyMM", compose.dateFormat());
        assertEquals(new Integer(3), compose.getCustomReader().read(null, 0, 0 , null));

        assertTrue(compose.hasCustomSource());
        assertEquals(Integer.class, compose.getCustomSourceReturnType());
    }