printf("sampledev_file: '%s'\n", opt->sampledev_file_);
printf("sampledevs: \n");
key_value_storage_print(&opt->sampledevs_, " '", "' -> '", "'\n");
printf("sampledev_file: '%s'\n", opt->sampledev_file_);
printf("sampledevs: \n");
key_value_storage_print(&opt->sampledevs_, " '", "' -> '", "'\n");