extraBits += int(w.literalFreq[lengthCode]) * int(lengthExtraBits[lengthCode-lengthCodesStart])
		}
		for offsetCode := 4; offsetCode < numOffsets; offsetCode++ {
			// First four offset codes have extra size = 0.
			extraBits += int(w.offsetFreq[offsetCode]) * int(offsetExtraBits[offsetCode])
		}
	}

	// Figure out smallest code.
	// Fixed Huffman baseline.
	var literalEncoding = fixedLiteralEncoding

// Returns the offset code corresponding to a specific offset.
func offsetCode(off uint32) uint32 {
	if off < uint32(len(offsetCodes)) {
		return offsetCodes[off]
	}
	if off>>7 < uint32(len(offsetCodes)) {
		return offsetCodes[off>>7] + 14
	}
	return offsetCodes[off>>14] + 28