String[] s3 = new String[]{"c", "d"};
String[] s4 = new String[]{"a", "b", "c", "d"};
Constraint p = new IsEqual(s1);
assertTrue("Should equal itself", p.eval(s1));
assertTrue("Should equal a similar array", p.eval(s2));
assertTrue("Should not equal a different array", !p.eval(s3));
assertTrue("Should not equal a different sized array", !p.eval(s4));
}