private function normalizeRequestEncodingHeaderForZlib(Request $request, array $options)
{
$autoEncoding = $options[self::OP_AUTO_ENCODING];
if ($autoEncoding && $this->hasZlib) {
$request->setHeader('Accept-Encoding', 'gzip, identity');
} elseif ($autoEncoding) {
$request->removeHeader('Accept-Encoding');
}
}