module ActiveRecord::Inheritance::ClassMethods

def set_base_class # :nodoc:
  @base_class = if self == Base
    self
  else
    unless self < Base
      raise ActiveRecordError, "#{name} doesn't belong in a hierarchy descending from ActiveRecord"
    end
    if superclass == Base || superclass.abstract_class?
      self
    else
      superclass.base_class
    end
  end
end