function _setupChannels()
    {
        $set = array_flip(array_values($this->_channels));
        foreach ($this->configuration as $layer => $data) {
            $i = 1000;
            if (isset($data['__channels']) && is_array($data['__channels'])) {
                foreach ($data['__channels'] as $channel => $info) {
                    $set[$channel] = $i++;
                }
            }
        }
        $this->_channels = array_values(array_flip($set));
        $this->setChannels($this->_channels);
    }