lithium\util\Collection::valid PHP Method

    public function valid()
    {
        return key($this->_data) !== null;
    }

 /**
  * Tests objects and scalar values being appended to the collection.
  *
  * @return void
  */
 public function testValueAppend()
 {
     $collection = new Collection();
     $this->assertFalse($collection->valid());
     $this->assertEqual(0, count($collection));
     $collection->append(1);
     $this->assertEqual(1, count($collection));
     $collection->append(new stdClass());
     $this->assertEqual(2, count($collection));
     $this->assertEqual(1, $collection->current());
     $this->assertEqual(new stdClass(), $collection->next());
 }