# File lib/bundler/index.rb, line 115
    def use(other, override_dupes = false)
      return unless other
      other.each do |s|
        if (dupes = search_by_spec(s)) && dupes.any?
          @all_specs[s.name] = [s] + dupes
          next unless override_dupes
          self << s
        end
        self << s
      end
      self
    end