# File lib/aws/record/validators/presence.rb, line 24
      def validate_attribute record, attribute_name, value

        blank = case
        when value.nil?                 then true
        when value.is_a?(String)        then value !~ /\S/
        when value == false             then false # defeat false.blank? == true
        when value.respond_to?(:empty?) then value.empty?
        when value.respond_to?(:blank?) then value.blank?
        else false
        end

        record.errors.add(attribute_name, message) if blank

      end