public function testIncrement()
{
$entity = new Entity(array('data' => array('counter' => 0)));
$this->assertEqual(0, $entity->counter);
$entity->increment('counter');
$this->assertEqual(1, $entity->counter);
$entity->decrement('counter', 5);
$this->assertEqual(-4, $entity->counter);
$this->assertNull($entity->increment);
$entity->increment('foo');
$this->assertEqual(1, $entity->foo);
$this->assertFalse(isset($entity->bar));
$entity->bar = 'blah';
$entity->sync();
$this->expectException("/^Field 'bar' cannot be incremented.\$/");
$entity->increment('bar');
}