descends_from_active_record?

# File activerecord/lib/active_record/inheritance.rb, line 67
      def descends_from_active_record?
        if self == Base
          false
        elsif superclass.abstract_class?
          superclass.descends_from_active_record?
        else
          superclass == Base || !columns_hash.include?(inheritance_column)
        end
      end