def contains?(object)
      key, id = to_key_and_id(object)

      @graph[key].is_a?(Enumerable) ? @graph[key].include?(id) : @graph[key]
    end
def contains?(object)
      key, id = to_key_and_id(object)

      @graph[key].is_a?(Enumerable) ? @graph[key].include?(id) : @graph[key]
    end
Create a new instance of the object tracker.

 Determine if the object tracker has already picked this object up.