slices.SortFunc(codes, func(a, b huffmanCode) int {
		return cmp.Compare(a.code, b.code)
	})

	t.nodes = make([]huffmanNode, len(codes))
	_, err := buildHuffmanNode(&t, codes, 0)
	return t, err
}

// huffmanSymbolLengthPair contains a symbol and its code length.
type huffmanSymbolLengthPair struct {
	value  uint16
	length uint8
}

// huffmanCode contains a symbol, its code and code length.