m->devices = hashmap_new(string_hash_func, string_compare_func);
m->seats = hashmap_new(string_hash_func, string_compare_func);
m->sessions = hashmap_new(string_hash_func, string_compare_func);
m->devices = hashmap_new(string_hash_func, string_compare_func);
m->seats = hashmap_new(string_hash_func, string_compare_func);
m->sessions = hashmap_new(string_hash_func, string_compare_func);