# File lib/bundler/index.rb, line 81
    def use(other, override_dupes = false)
      return unless other
      other.each do |s|
        if (dupes = search_by_spec(s)) && dupes.any?
          next unless override_dupes
          @specs[s.name] -= dupes
        end
        @specs[s.name] << s
      end
      self
    end