Retrieves every value inside hash_table. The returned data
is valid until hash_table is modified.
This iterates over every entry in the hash table to build its return value.
To iterate over the entries in a glib.HashTable more efficiently, use a
a GList containing all the values
inside the hash table. The content of the list is owned by the
hash table and should not be modified or freed. Use g_list_free()
when done using the list.