+XBT_PUBLIC(void) sg_host_turn_on(sg_host_t host);
+#define MSG_host_on(h) sg_host_turn_on(h)
+XBT_PUBLIC(void) sg_host_turn_off(sg_host_t host);
+#define MSG_host_off(h) sg_host_turn_off(h)
+XBT_PUBLIC(int) sg_host_is_on(sg_host_t host);
+#define MSG_host_is_on(h) sg_host_is_on(h)
+XBT_PUBLIC(int) sg_host_is_off(sg_host_t host);
+#define MSG_host_is_off(h) sg_host_is_off(h)
+