PopTest\Db\PredicateTest::testIsNull PHP Method

    public function testIsNull()
    {
        $p = new Predicate(Sql::factory(Db::factory('Sqlite', array('database' => __DIR__ . '/../tmp/test.sqlite')), 'users'));
        $p->isNull('email');
        $this->assertEquals('("email" IS NULL)', (string) $p);
    }