protected function update($namespace, $config) {
		foreach ($config as $k => $v) {
			if (strpos($k, '.') === false) {
				$this->cache[$namespace][$k] = $v;
				continue;
			}
			$keys = explode('.', $k);
			$total = count($keys) - 1;
			$parent = &$this->cache[$namespace];
			foreach ($keys as $kk => $vv) {
				if ($total === $kk) {
					$parent[$vv] = $v;
				} else {
					if (!isset($parent[$vv])) {
						$parent[$vv] = [];
					}
					$parent = &$parent[$vv];
				}
			}
		}
	}