class Bundler::Index

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