public function testAllowsFunctionalFilter()
{
$this->coll->merge(array('fruit' => 'apple', 'number' => 'ten', 'prepositions' => array('about', 'above', 'across', 'after'), 'same_number' => 'ten'));
$filtered = $this->coll->filter(function ($key, $value) {
return $value == 'ten';
});
$this->assertNotEquals($filtered, $this->coll);
$this->assertEquals(array('number' => 'ten', 'same_number' => 'ten'), $filtered->getAll());
}