network ?: 'public'; $suffix = $request->endpointSuffix; if ($network === 'public') { $network = ''; } if ($request->endpointRegional === 'regional') { $regionId = $request->realRegionId(); return "{$request->product}{$suffix}{$network}.{$regionId}.aliyuncs.com"; } if ($request->endpointRegional === 'central') { return "{$request->product}{$suffix}{$network}.aliyuncs.com"; } throw new InvalidArgumentException('endpointRegional is invalid.'); } }