public function testIteratorInterface()
{
$t1 = new WordToken('a');
$t2 = new WordToken('b');
$r = new TokenRegistry();
$r->add($t1);
$r->add($t2);
$r->rewind();
$this->assertEquals(0, $r->key());
$this->assertSame($t1, $r->current());
$r->next();
$this->assertTrue($r->valid());
$this->assertEquals(1, $r->key());
$this->assertSame($t2, $r->current());
$r->next();
$this->assertFalse($r->valid());
}
