to_json (DataMapper::Serialize)

    # File lib/dm-serializer/to_json.rb, line 10
        def to_json(*args)
          options = args.first || {}

          result = {}

          propset = properties_to_serialize(options)

          propset.each do |property|
            result[property.name] = send(property.name)
          end

          # add methods
          (options[:methods] || []).each do |meth|
            if self.respond_to?(meth)
              result[meth] = send(meth)
            end
          end

          # Note: if you want to include a whole other model via relation, use :methods
          # comments.to_json(:relationships=>{:user=>{:include=>[:first_name],:methods=>[:age]}})
          # add relationships
          # TODO: This needs tests and also needs to be ported to #to_xml and #to_yaml
          (options[:relationships] || {}).each do |rel,opts|
            if self.respond_to?(rel)
              result[rel] = send(rel).to_json(opts.merge(:to_json => false))
            end
          end

          # default to making JSON
          if options.fetch(:to_json, true)
            result.to_json
          else
            result
          end
        end