@Test public void testSubtractFromSetWithEOF() throws Exception {
		IntervalSet s = IntervalSet.of(10,20);
		s.add(Token.EOF);
		IntervalSet s2 = IntervalSet.of(12,15);
		String expecting = "{<EOF>, 10..11, 16..20}";
		String result = (s.subtract(s2)).toString();
		assertEquals(expecting, result);
	}
Public default constructor used by TestRig
tool-testsuite/test/org/antlr/v4/test/tool/TestIntervalSet.java