code: @NotNull
      public final String marshal(@NotNull final SerializerRegistry registry, 
              @NotNull final CommonEvent commonEvent) {
  
          Contract.requireArgNotNull("registry", registry);
          Contract.requireArgNotNull("commonEvent", commonEvent);
  
          final Serializer serializer = registry.getSerializer(EscEvent.SER_TYPE);
  
          final EscEvent event = createEscEvent(registry, serializer.getMimeType(), commonEvent);
          final byte[] data = serializer.marshal(event, EscEvent.SER_TYPE);
          return new String(data, serializer.getMimeType().getEncoding());
      }
docs: Creates a single "application/vnd.eventstore.events(+json/+xml)" entry surrounded by "[]" (JSON) or
  "&lt;Events&gt;&lt;/Events&gt;" (XML).
  
  @param registry
  Registry with known serializers.
  @param commonEvent
  Event to marshal.
  
  @return Single event body.