public function testClear()
{
$admin = ini_get('xcache.admin.enable_auth') === "On";
$this->skipIf($admin, "XCache::clear() test skipped due to authentication.");
$key1 = 'key_clear_1';
$key2 = 'key_clear_2';
$time = strtotime('+1 minute');
$result = xcache_set($key1, 'data that will no longer exist', $time);
$this->assertTrue($result);
$result = xcache_set($key2, 'more dead data', $time);
$this->assertTrue($result);
$result = $this->XCache->clear();
$this->assertTrue($result);
$this->assertNull(xcache_get($key1));
$this->assertNull(xcache_get($key2));
}