Adding review comments

Author: cbuescher

core/src/main/java/org/elasticsearch/search/aggregations/ParsedAggregation.java

@@ -63,8 +63,6 @@ public final Map<String, Object> getMetaData() {
     //TODO it may make sense to move getType to the Aggregation interface given that we are duplicating it in both implementations
     protected abstract String getType();
 
-    //TODO the only way to avoid duplicating this method is making Aggregation extend ToXContent
-    //and declare toXContent as a default method in it. Doesn't sound like the right thing to do.
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params params) throws IOException {
         // Concatenates the type and the name of the aggregation (ex: top_hits#foo)

core/src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/ParsedCardinality.java

@@ -23,7 +23,6 @@
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.DocValueFormat;
-import org.elasticsearch.search.aggregations.InternalAggregation.CommonFields;
 import org.elasticsearch.search.aggregations.ParsedAggregation;
 
 import java.io.IOException;

core/src/test/java/org/elasticsearch/search/aggregations/metrics/cardinality/InternalCardinalityTests.java

@@ -44,7 +44,6 @@
 import java.util.List;
 import java.util.Map;
 
-import static org.elasticsearch.common.xcontent.XContentHelper.toXContent;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertToXContentEquivalent;
 
 public class InternalCardinalityTests extends InternalAggregationTestCase<InternalCardinality> {
@@ -93,8 +92,8 @@ public void testFromXContent() throws IOException {
         String name = cardinality.getName();
         ToXContent.Params params = new ToXContent.MapParams(Collections.singletonMap(RestSearchAction.TYPED_KEYS_PARAM, "true"));
         boolean humanReadable = randomBoolean();
-        XContentType xContentType = XContentType.JSON; //randomFrom(XContentType.values());
-        BytesReference originalBytes = toXContent(cardinality, xContentType, params, humanReadable);
+        XContentType xContentType = randomFrom(XContentType.values());
+        BytesReference originalBytes = toShuffledXContent(cardinality, xContentType, params, humanReadable);
         ParsedCardinality parsed;
         try (XContentParser parser = createParser(xContentType.xContent(), originalBytes)) {
             assertEquals(XContentParser.Token.START_OBJECT, parser.nextToken());