gistfile1.rb

    def count(*args)
      query         = args.last.kind_of?(Hash) ? args.pop : {}
      property_name = args.first

      if property_name
        assert_kind_of 'property', property_by_name(property_name), Property
      end

      aggregate(query.merge(:fields => [ property_name ? property_name.count : :all.count ]))
    end