output: #fixed code
                                  @Test
      public void testResponseContentOverwriteHeaders() throws Exception {
          ResponseContent interceptor = new ResponseContent(true);
          HttpContext context = new BasicHttpContext(null);
          HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, HttpStatus.SC_OK, "OK");
          response.addHeader(new BasicHeader(HTTP.CONTENT_LEN, "10"));
          response.addHeader(new BasicHeader(HTTP.TRANSFER_ENCODING, "whatever"));
          interceptor.process(response, context);
          Assert.assertEquals("0", response.getFirstHeader(HTTP.CONTENT_LEN).getValue());
      }
input: #vulnerable code 
                                  @Test
      public void testResponseContentOverwriteHeaders() throws Exception {
          ResponseContent interceptor = new ResponseContent(true);
          HttpContext context = new BasicHttpContext(null);
          HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, HttpStatus.SC_OK, "OK");
          response.addHeader(new BasicHeader(HTTP.CONTENT_LEN, "10"));
          response.addHeader(new BasicHeader(HTTP.TRANSFER_ENCODING, "whatever"));
          interceptor.process(response, context);
          Assert.assertEquals("0", response.getFirstHeader(HTTP.CONTENT_LEN).getValue());
          Assert.assertEquals("whatever", response.getFirstHeader(HTTP.TRANSFER_ENCODING).getValue());
      } 
                              #location 10 
                              #vulnerability type NULL_DEREFERENCE