+int show_cgroup_and_extra_by_spec(const char *spec, const char *prefix, unsigned n_columns, bool kernel_threads, const pid_t extra_pids[], unsigned n_extra_pids, OutputFlags flags);
+int show_cgroup_and_extra(const char *controller, const char *path, const char *prefix, unsigned n_columns, bool kernel_threads, const pid_t extra_pids[], unsigned n_extra_pids, OutputFlags flags);