code: @Override
      public ContentSerializer getContentSerializerForContentType(String contentType) {
          for (ContentSerializer renderer : serializers) {
              if (renderer.getContentType().equals(contentType)) {
                  return renderer;
              }
          }
          LoggerFactory.getLogger(this.getClass()).info("Cannot find a content renderer handling " + contentType);
          return null;
      }
docs: Gets the content serializer that can be used to serialize a result to the given content type. This method uses
  an exact match.
  
  @param contentType the content type
  @return a content serializer, {@code null} if none match