* @return 1 if color @p col could be applied, 0 otherwise
*/
static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, struct list_head *changed)
* @return 1 if color @p col could be applied, 0 otherwise
*/
static int change_node_color(co_mst_env_t *env, co_mst_irn_t *node, int tgt_col, struct list_head *changed)