# File lib/test/unit/assertions.rb, line 504
      def assert_not_match(regexp, string, message="")
        _wrap_assertion do
          assert_instance_of(Regexp, regexp,
                             "<REGEXP> in assert_not_match(<REGEXP>, ...) " +
                             "should be a Regexp.")
          full_message = build_message(message,
                                       "<?> expected to not match\n<?>.",
                                       regexp, string)
          assert_block(full_message) { regexp !~ string }
        end
      end