module ActiveRecord::Core::ClassMethods

def inherited(subclass)
  super
  # initialize cache at class definition for thread safety
  subclass.initialize_find_by_cache
  unless subclass.base_class?
    klass = self
    until klass.base_class?
      klass.initialize_find_by_cache
      klass = klass.superclass
    end
  end
  subclass.class_eval do
    @arel_table = nil
    @predicate_builder = nil
    @inspection_filter = nil
    @filter_attributes ||= nil
    @generated_association_methods ||= nil
  end
end