text: #ifndef HASH_MAP_H
  #define HASH_MAP_H
  
  #include <sys/types.h>
  
  typedef struct {
    size_t size;
    size_t capacity;
    void **keys;
    void **values;
  } HashMap;
  
  HashMap *HashMap_new(size_t capacity);
  void HashMap_destroy(HashMap *hash_map);
  void HashMap_insert(HashMap **hash_map_ref, void *const key, void *const value);
  void *HashMap_lookup(HashMap *hash_map, void *const key);
  
  #endif //HASH_MAP_H
  