output: #fixed code
                               @Test
  	public void writeXml_data() {
  		Attachment prop = new Attachment("image/png", "data".getBytes());
  		assertWriteXml("<binary>" + Base64.encodeBase64String("data".getBytes()) + "</binary>", prop, marshaller);
  	}
input: #vulnerable code 
                               @Test
  	public void writeXml_data() {
  		Attachment prop = new Attachment("image/png", "data".getBytes());
  
  		Document actual = xcalProperty(marshaller);
  		marshaller.writeXml(prop, XmlUtils.getRootElement(actual));
  
  		Document expected = xcalProperty(marshaller, "<binary>" + Base64.encodeBase64String("data".getBytes()) + "</binary>");
  		assertXMLEqual(expected, actual);
  	} 
                              #location 6 
                              #vulnerability type NULL_DEREFERENCE