Muszę policzyć duplikaty, muszą być w 100% identyczne, aby zwiększyć moją liczbę, ale nie mogę nic nie używać z Ruby 1.8.5, ten kod będzie działał wewnątrz wtyczki w google sketchup

Google Sketchup Ruby API

puts VERSION
1.8.5

puts RUBY_PLATFORM
i686-darwin8.10.1

product = 'Glass'
x = width
y = length
z = density

product_list = [
                { "product" => 1, "x" => 200, "y" => 100, "z" => 18},
                { "product" => 1, "x" => 200, "y" => 100, "z" => 18},
                { "product" => 1, "x" => 300, "y" => 100, "z" => 18},
                { "product" => 2, "x" => 300, "y" => 100, "z" => 18},
                { "product" => 2, "x" => 100, "y" => 100, "z" => 18},
                { "product" => 2, "x" => 100, "y" => 100, "z" => 18},
                { "product" => 3, "x" => 100, "y" => 100, "z" => 18}
               ];

product_list_result = product_list.count_duplicate();

product_list_result = [
     { "product" => 1, "x" => 200, "y" => 100, "z" => 18, "count" = 2},
     { "product" => 1, "x" => 300, "y" => 100, "z" => 18, "count" = 1},
     { "product" => 2, "x" => 300, "y" => 100, "z" => 18, "count" = 1},
     { "product" => 2, "x" => 100, "y" => 100, "z" => 18, "count" = 2},
     { "product" => 3, "x" => 100, "y" => 100, "z" => 18, "count" = 1}
                      ];