subclass_from_attributes

# File activerecord/lib/active_record/inheritance.rb, line 208
      def subclass_from_attributes(attrs)
        subclass_name = attrs.with_indifferent_access[inheritance_column]

        if subclass_name.present? && subclass_name != self.name
          subclass = subclass_name.safe_constantize

          unless descendants.include?(subclass)
            raise ActiveRecord::SubclassNotFound.new("Invalid single-table inheritance type: #{subclass_name} is not a subclass of #{name}")
          end

          subclass
        end
      end