@Override
	public String toString() { return toString(false); }
Are two IntervalSets equal?  Because all intervals are sorted
 and disjoint, equals is a simple linear walk over both lists
 to make sure they are the same.  Interval.equals() is used
 by the List.equals() method to check the ranges.
runtime/Java/src/org/antlr/v4/runtime/misc/IntervalSet.java