public function testWriteAndClear()
{
$key = 'key_to_clear';
$data = 'data to be cleared';
$keys = array($key);
$expiry = null;
$result = $this->Memory->write(array($key => $data), $expiry);
$this->assertTrue($result);
$this->assertEqual($this->Memory->cache, $result);
$key2 = 'key2_to_clear';
$data2 = 'data to be cleared';
$result = $this->Memory->write(array($key2 => $data2), $expiry);
$this->assertTrue($result);
$this->assertEqual($this->Memory->cache, $result);
$result = $this->Memory->clear();
$this->assertTrue($result);
$this->assertEqual(array(), $this->Memory->cache);
$result = $this->Memory->write(array($key => $data), $expiry);
$this->assertTrue($result);
$this->assertEqual($this->Memory->cache, $result);
$result = $this->Memory->clear();
$this->assertTrue($result);
$this->assertEqual(array(), $this->Memory->cache);
}