key (DataMapper::Resource)

    # File lib/dm-core/resource.rb, line 86
        def key
          return @key if defined?(@key)

          key = model.key(repository_name).map do |property|
            original_attributes[property] || (property.loaded?(self) ? property.get!(self) : nil)
          end

          return unless key.all?

          # memoize the key if the Resource is not frozen
          @key = key unless frozen?

          key
        end