public function testKeys()
{
$resultSet = new ResultSet(array('a' => array('_id' => 'a', 'field' => 'value1'), 'b' => array('_id' => 'b', 'field' => 'value2'), 'c' => array('_id' => 'c', 'field' => 'value3')));
$values = $resultSet->keys();
$this->assertEquals(array('a', 'b', 'c'), $values);
}