bool hashmap_contains(Hashmap *h, const void *key);
void* hashmap_remove(Hashmap *h, const void *key);
void* hashmap_remove_value(Hashmap *h, const void *key, void *value);
bool hashmap_contains(Hashmap *h, const void *key);
void* hashmap_remove(Hashmap *h, const void *key);
void* hashmap_remove_value(Hashmap *h, const void *key, void *value);