#vulnerable code 
                                @Test
    public void pushTwiceToWebsite() throws IOException, URISyntaxException {
        Swift swift = new Swift()
                .setOnFileObjectStore("websites");
        website = new WebsiteMock(new AccountMock(swift), "website");
        website.pushDirectory(FileAction.getFile("object-store/container1"));
        String lastModified1 = website.getObject("checkmark.png").getLastModified();
        website.pushDirectory(FileAction.getFile("object-store/container1"));
        String lastModified2 = website.getObject("checkmark.png").getLastModified();
        assertEquals(lastModified1, lastModified2);
        assertEquals(2, website.list().size());
    } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void pushTwiceToWebsite() throws IOException, URISyntaxException {
        Swift swift = new Swift()
                .setOnFileObjectStore("websites", false);
        website = new WebsiteMock(new AccountMock(swift), "website");
        website.pushDirectory(FileAction.getFile("object-store/container1"));
        String lastModified1 = website.getObject("checkmark.png").getLastModified();
        website.pushDirectory(FileAction.getFile("object-store/container1"));
        String lastModified2 = website.getObject("checkmark.png").getLastModified();
        assertEquals(lastModified1, lastModified2);
        assertEquals(2, website.list().size());
    }