public function write($key, $value = null, array $options = array()) {
		$expire = (!isset($options['expire']) && empty($this->_config['expire']));
		$config = $this->_config;
		$cookieClass = __CLASS__;

		if ($expire && $key != $config['name']) {
			return null;
		}
		$expires = (isset($options['expire'])) ? $options['expire'] : $config['expire'];

		return function($self, $params) use (&$config, &$expires, $cookieClass) {
			$key = $params['key'];
			$value = $params['value'];
			$key = array($key => $value);
			if (is_array($value)) {
				$key = Set::flatten($key);
			}

			foreach ($key as $name => $val) {
				$name = $cookieClass::keyFormat($name, $config);
				$result = setcookie($name, $val, strtotime($expires), $config['path'],
					$config['domain'], $config['secure'], $config['httponly']
				);

				if (!$result) {
					throw new RuntimeException("There was an error setting {$name} cookie.");
				}
			}
			return true;
		};
	}