public function addFilter($name, $attributes = array())
    {
        // name is "filtername:method:alias".
        $names = explode(':', $name);
        $filter = array_shift($names);
        $method = array_shift($names);
        $alias = array_shift($names);
        if (! $alias) $alias = $filter;
        if (! is_array($attributes)) $attributes = [];

        // method miss match, when return.
        if ($method && strtoupper($method) !== $this->Request->getMethod()) return;

        // register.
        if (isset($this->filters[$alias])) {
            $this->filters[$alias]['attributes'] = $this->arrayUtil->merge($this->filters[$alias]['attributes'], $attributes);
        } else {
            $this->filter_names[] = $alias;
            $this->filters[$alias] = array('name' => $filter, 'attributes' => (array)$attributes);
        }

        // if action filter.
        if (strtolower($filter) === 'action') {
            $this->has_action_filter = true;
        }
    }