#vulnerable code 
                             @Test
	public void testPostBinaryUTF8() throws URISyntaxException {
		HttpResponse<JsonNode> response = Unirest.post("http://httpbin.org/post").field("param3", "こんにちは").field("file", new File(getClass().getResource("/test").toURI())).asJson();

		assertEquals("This is a test file", response.getBody().getObject().getJSONObject("files").getString("file"));
		assertEquals("こんにちは", response.getBody().getObject().getJSONObject("form").getString("param3"));
	} 
                            #location 5 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @Test
	public void testPostBinaryUTF8() throws URISyntaxException {
		HttpResponse<JsonNode> response = Unirest.post(MockServer.POST)
				.header("Accept", ContentType.MULTIPART_FORM_DATA.getMimeType())
				.field("param3", "こんにちは")
				.field("file", new File(getClass().getResource("/test").toURI()))
				.asJson();

		FormCapture json = TestUtils.read(response, FormCapture.class);
		json.assertQuery("param3", "こんにちは");
		json.getFile("test").assertBody("This is a test file");
	}