@Override
 public void writeTo(StreamOutput out) throws IOException {
   out.writeVInt(processorResults.size());
   for (SimulateProcessorResult result : processorResults) {
     result.writeTo(out);
   }
 }
 @Override
 public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
   builder.startObject();
   builder.startArray("processor_results");
   for (SimulateProcessorResult processorResult : processorResults) {
     processorResult.toXContent(builder, params);
   }
   builder.endArray();
   builder.endObject();
   return builder;
 }