+ r = sd_memfd_new_and_map(&f, STRING_SIZE, (void**) &s);
+ assert_se(r >= 0);
+
+ for (i = 0; i < STRING_SIZE-1; i++)
+ s[i] = '0' + (i % 10);
+
+ s[STRING_SIZE-1] = 0;
+ munmap(s, STRING_SIZE);
+
+ r = sd_memfd_get_size(f, &sz);
+ assert_se(r >= 0);
+ assert_se(sz == STRING_SIZE);
+
+ r = sd_bus_message_append_string_memfd(m, f);
+ assert_se(r >= 0);
+
+ sd_memfd_free(f);
+