@Test public void testNotEqualSet() throws Exception {
		IntervalSet vocabulary = IntervalSet.of(1,1000);
		IntervalSet s = IntervalSet.of(1,1000);
		String expecting = "{}";
		String result = (s.complement(vocabulary)).toString();
		assertEquals(expecting, result);
	}
Public default constructor used by TestRig
tool-testsuite/test/org/antlr/v4/test/tool/TestIntervalSet.java