int unit_name_to_instance(const char *n, char **instance);
char* unit_name_to_prefix(const char *n);
char* unit_name_to_prefix_and_instance(const char *n);
int unit_name_to_instance(const char *n, char **instance);
char* unit_name_to_prefix(const char *n);
char* unit_name_to_prefix_and_instance(const char *n);