void *, void *);
int hash_table_contains (const struct hash_table *, const void *);
-void hash_table_put (struct hash_table *, const void *, void *);
+void hash_table_put (struct hash_table *, const void *, const void *);
int hash_table_remove (struct hash_table *, const void *);
void hash_table_clear (struct hash_table *);