#vulnerable code 
                                public void testBase64() {
        String content = "Hello World";
        String encodedContent;
        encodedContent = new String(Base64.encodeBase64(content.getBytes()));
        assertTrue("encoding hello world", encodedContent.equals("SGVsbG8gV29ybGQ="));
    } 
                            #location 4 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public void testBase64() {
        String content = "Hello World";
        String encodedContent;
        byte[] encodedBytes = Base64.encodeBase64(StringUtils.getBytesUtf8(content));
        encodedContent = StringUtils.newStringUtf8(encodedBytes);
        assertTrue("encoding hello world", encodedContent.equals("SGVsbG8gV29ybGQ="));
    }