in hpack/src/main/java/com/twitter/hpack/Encoder.java [173:182]
private void encodeStringLiteral(OutputStream out, byte[] string) throws IOException {
int huffmanLength = Huffman.ENCODER.getEncodedLength(string);
if ((huffmanLength < string.length && !forceHuffmanOff) || forceHuffmanOn) {
encodeInteger(out, 0x80, 7, huffmanLength);
Huffman.ENCODER.encode(out, string);
} else {
encodeInteger(out, 0x00, 7, string.length);
out.write(string, 0, string.length);
}
}