module ActiveSupport::DescendantsTracker

def clear
  if defined? ActiveSupport::Dependencies
    @@direct_descendants.each do |klass, descendants|
      if ActiveSupport::Dependencies.autoloaded?(klass)
        @@direct_descendants.delete(klass)
      else
        descendants.reject! { |v| ActiveSupport::Dependencies.autoloaded?(v) }
      end
    end
  else
    @@direct_descendants.clear
  end
end