_read_attribute

# File activerecord/lib/active_record/attribute_methods/read.rb, line 110
      def _read_attribute(attr_name)
        attr_name = attr_name.to_s
        attr_name = self.class.primary_key if attr_name == 'id'
        value = @attributes[attr_name]
        unless value.nil?
          if column = column_for_attribute(attr_name)
            if unserializable_attribute?(attr_name, column)
              unserialize_attribute(attr_name)
            else
              column.type_cast(value)
            end
          else
            value
          end
        end
      end