reset_subclasses

# File activerecord/lib/active_record/base.rb, line 402
    def self.reset_subclasses #:nodoc:
      nonreloadables = []
      subclasses.each do |klass|
        unless ActiveSupport::Dependencies.autoloaded? klass
          nonreloadables << klass
          next
        end
        klass.instance_variables.each { |var| klass.send(:remove_instance_variable, var) }
        klass.instance_methods(false).each { |m| klass.send :undef_method, m }
      end
      @@subclasses = {}
      nonreloadables.each { |klass| (@@subclasses[klass.superclass] ||= []) << klass }
    end