    # File lib/rubygems/specification.rb, line 162
        def self.attribute(name, default=nil)
          ivar_name = "@#{name}".intern
          if default.nil? then
            @@nil_attributes << ivar_name
          else
            @@non_nil_attributes << [ivar_name, default]
          end

          @@attributes << [name, default]
          @@default_value[name] = default
          attr_accessor(name)
        end