NORELEASE for getWriteableName in aggregations base class

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

@@ -190,6 +190,7 @@ public abstract class AggregatorBuilder<AB extends AggregatorBuilder<AB>> extend
 
     @Override
     public String getWriteableName() {
+        // NORELEASE remove this before 5.0.0GA - all builders will implement this method on their own.
         return type.stream().toUtf8();
     }
 

core/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/HistogramAggregatorBuilder.java

@@ -51,4 +51,8 @@ public class HistogramAggregatorBuilder extends AbstractHistogramBuilder<Histogr
                 parent, subFactoriesBuilder, metaData);
     }
 
+    @Override
+    public String getWriteableName() {
+        return NAME;
+    }
 }