# File lib/chef/node.rb, line 441
    def expand!(data_source = 'server')
      expansion = run_list.expand(chef_environment, data_source)
      raise Chef::Exceptions::MissingRole, expansion if expansion.errors?

      self.tags # make sure they're defined

      @automatic_attrs[:recipes] = expansion.recipes
      @automatic_attrs[:roles] = expansion.roles

      expansion
    end