# File lib/logging.rb, line 328
    def format_as( f )
      f = f.intern if f.instance_of? String

      unless [:string, :inspect, :yaml, :json].include? f
        raise ArgumentError, "unknown object format '#{f}'"
      end

      module_eval "OBJ_FORMAT = :#{f}", __FILE__, __LINE__
      self
    end