public function testNotEquals()
 {
     $constraintList1 = new ConstraintList(array(new SingleValueConstraint()));
     $constraintList2 = new ConstraintList(array(new MultiValueConstraint()));
     $constraintList3 = new ConstraintList(array());
     $this->assertFalse($constraintList1->equals($constraintList2));
     $this->assertFalse($constraintList1->equals($constraintList3));
     $this->assertFalse($constraintList1->equals(null));
 }