handle_dependency

# File activerecord/lib/active_record/associations/has_one_association.rb, line 7
      def handle_dependency
        case options[:dependent]
        when :restrict_with_exception
          raise ActiveRecord::DeleteRestrictionError.new(reflection.name) if load_target

        when :restrict_with_error
          if load_target
            record = klass.human_attribute_name(reflection.name).downcase
            owner.errors.add(:base, :"restrict_dependent_destroy.one", record: record)
            false
          end

        else
          delete
        end
      end