code: public boolean isIntervalComparable(Interval<E> other)
    {
      int flags = getRelationFlags(other);
      if (checkMultipleBitSet(flags & REL_FLAGS_INTERVAL_UNKNOWN)) {
        return false;
      }
      return checkFlagSet(flags, REL_FLAGS_INTERVAL_BEFORE) || checkFlagSet(flags, REL_FLAGS_INTERVAL_AFTER);
    }
docs: Checks whether this interval is comparable with another interval
  comes before or after
  @param other interval to compare with