add another instance test

src/test/java/de/tla2b/examples/InstanceTest.java

@@ -25,6 +25,12 @@ public class InstanceTest {
 		runModule(file);
 	}
 
+	@Test
+	public void testModConstantAssignment() throws Exception {
+		String file = "src/test/resources/examples/instance/Counter/ModConstantAssignment.tla";
+		runModule(file);
+	}
+
 	@Test
 	public void testOneInstanced() throws Exception {
 		String file = "src/test/resources/examples/instance/Counter/OneInstanced.tla";