# File lib/pdf/reader/content.rb, line 451
    def resolve_references(obj)
      case obj
      when PDF::Reader::Stream then
        obj.hash = resolve_references(obj.hash)
        obj
      when PDF::Reader::Reference then
        resolve_references(@xref.object(obj))
      when Hash                   then obj.each { |key,val| obj[key] = resolve_references(val) }
      when Array                  then obj.collect { |item| resolve_references(item) }
      else
        obj
      end
    end