Add topAnswers to Retrieve and Rank, closes #456

Author: germanattanasio

retrieve-and-rank/src/main/java/com/ibm/watson/developer_cloud/retrieve_and_rank/v1/RetrieveAndRank.java

@@ -334,15 +334,18 @@ public ServiceCall<Ranking> rank(final String rankerID, final File answers, Inte
     final JsonObject contentJson = new JsonObject();
     contentJson.addProperty(ANSWERS, ((topAnswers != null) && (topAnswers > 0)) ? topAnswers : 10);
 
-    final RequestBody body = new MultipartBody.Builder().setType(MultipartBody.FORM)
-        .addPart(Headers.of(HttpHeaders.CONTENT_DISPOSITION, "form-data; name=\"answer_data\""),
-            RequestBody.create(HttpMediaType.BINARY_FILE, answers))
-        .addPart(Headers.of(HttpHeaders.CONTENT_DISPOSITION, "form-data; name=\"answer_metadata\""),
-            RequestBody.create(HttpMediaType.TEXT, contentJson.toString()))
-        .build();
+    okhttp3.MultipartBody.Builder builder =  new MultipartBody.Builder()
+        .setType(MultipartBody.FORM)
+        .addPart(Headers.of(
+            HttpHeaders.CONTENT_DISPOSITION, "form-data; name=\"answer_data\""),
+            RequestBody.create(HttpMediaType.BINARY_FILE, answers)
+        );
+
+    if (topAnswers != null)
+      builder.addFormDataPart(ANSWERS, topAnswers.toString());
 
     final String path = String.format(PATH_RANK, rankerID);
-    final Request request = RequestBuilder.post(path).body(body).build();
+    final Request request = RequestBuilder.post(path).body(builder.build()).build();
     return createServiceCall(request, ResponseConverterUtils.getObject(Ranking.class));
   }
 

tests/src/test/java/com/ibm/watson/developer_cloud/retrieve_and_rank/v1/RetrieveAndRankTest.java

@@ -509,8 +509,10 @@ public void testRankerRank1() throws FileNotFoundException, InterruptedException
     Ranking serviceResponse = service.rank(ANY_RANKER_ID, rankFile, numToRank).execute();
     RecordedRequest request = server.takeRequest();
 
+    String body = request.getBody().readUtf8();
     assertEquals(RANK_URL, request.getPath());
     assertEquals("POST", request.getMethod());
+    assertTrue(body.contains("Content-Disposition: form-data; name=\"answers\""));
     assertNotNull(request.getHeader(HttpHeaders.AUTHORIZATION));
     assertEquals(mockResponse, serviceResponse);
     assertEquals(request.getHeader(HttpHeaders.ACCEPT), HttpMediaType.APPLICATION_JSON);