private Formula(byte[] byteEncoding, int encodedTokenLen) {
_byteEncoding = byteEncoding;
_encodedTokenLen = encodedTokenLen;
if (false) { // set to true to eagerly check Ptg decoding
LittleEndianByteArrayInputStream in = new LittleEndianByteArrayInputStream(byteEncoding);
Ptg.readTokens(encodedTokenLen, in);
int nUnusedBytes = _byteEncoding.length - in.getReadIndex();
if (nUnusedBytes > 0) {
// TODO - this seems to occur when IntersectionPtg is present
// This example file "IntersectionPtg.xls"
// used by test: TestIntersectionPtg.testReading()
// has 10 bytes unused at the end of the formula