void unit_file_changes_free(UnitFileChange *changes, unsigned n_changes);
int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char *name);
void unit_file_changes_free(UnitFileChange *changes, unsigned n_changes);
int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char *name);