validate

# File activerecord/lib/active_record/validations/presence.rb, line 4
      def validate(record)
        super
        attributes.each do |attribute|
          next unless record.class._reflect_on_association(attribute)
          associated_records = Array.wrap(record.send(attribute))

          # Superclass validates presence. Ensure present records aren't about to be destroyed.
          if associated_records.present? && associated_records.all? { |r| r.marked_for_destruction? }
            record.errors.add(attribute, :blank, options)
          end
        end
      end