# File lib/active_record/observer.rb, line 113
    def initialize
      observed_classes = [ observed_class ].flatten
      observed_subclasses_class = observed_classes.collect {|c| c.send(:subclasses) }.flatten!
      (observed_classes + observed_subclasses_class).each do |klass| 
        klass.add_observer(self)
        klass.send(:define_method, :after_find) unless klass.respond_to?(:after_find)
      end
    end