uint64_t
TimeStampValue::operator-(const TimeStampValue &aOther) const
{
  if (mIsNull && aOther.mIsNull)
    return uint64_t(0);

  return CheckQPC(aOther);
}
uint64_t
TimeStampValue::operator-(const TimeStampValue &aOther) const
{
  if (mIsNull && aOther.mIsNull)
    return uint64_t(0);

  if (CheckQPC(int64_t(mGTC - aOther.mGTC), aOther))
    return mQPC - aOther.mQPC;

  return mGTC - aOther.mGTC;
}