HashTableIter
Description:
Initializes a key/value pair iterator and associates it with hash_table.
Modifying the hash table after calling this function invalidates the returned iterator.
The iteration order of a GenericSetIter over the keys/values in a hash table is not defined.
GHashTableIter iter;
gpointer key, value;
g_hash_table_iter_init (&iter, hash_table);
while (g_hash_table_iter_next (&iter, &key, &value))
  {
    // do something with key and value
  }
    
    Parameters:
| this | 
           an uninitialized GenericSetIter  | 
      
| hash_table |