redef fun serialize_reference(object)
	do
		if cache.has_object(object) then
			# Cycle
			var id = object.object_id
			if inspect_testing then id = cache.id_for(object)

			stream.write "<"
			stream.write object.class_name
			stream.write "#"
			stream.write id.to_s
			stream.write ">"
		else if object != first_object and (not object isa DirectSerializable) then
			# Another object, print class and id only
			var id = object.object_id
			if inspect_testing then id = cache.new_id_for(object)

			stream.write "<"
			stream.write object.class_name
			stream.write "#"
			stream.write id.to_s
			stream.write ">"
		else
			# Main object
			serialize object
		end
	end

	redef fun serialize_reference(object)
	do
		if not plain_json and cache.has_object(object) then
			# if already serialized, add local reference
			var id = cache.id_for(object)
			stream.write "\{"
			indent_level += 1
			new_line_and_indent
			stream.write "\"__kind\": \"ref\", \"__id\": "
			stream.write id.to_s
			indent_level -= 1
			new_line_and_indent
			stream.write "\}"
		else
			# serialize here
			serialize object
		end
	end

	redef fun serialize_reference(object)
	do
		if not plain_msgpack and cache.has_object(object) then
			# if already serialized, add local reference
			var id = cache.id_for(object)
			stream.write_msgpack_ext(ext_typ_ref, id.to_bytes)
		else
			# serialize
			serialize object
		end
	end

	# Remove caching when saving refs to db
	redef fun serialize_reference(object) do serialize object