+ * HASH_ZERO_FILL New entries should be initialized to all zeroes.
+ * HASH_TABLE_ALLOC The hash table itself will be allocated and freed using
+ * the same allocation functions as the nodes instead of
+ * the default xmalloc().
+ * HASH_TABLE_DYNAMIC Support multiple hash tables; the first parameter of all
+ * hash table operations is struct HASH_PREFIX(table) *.