public function responseHeaderCallback($ch, $header)
{
if (strpos($header, ':')) {
list($key, $value) = explode(':', $header, 2);
$value = trim($value);
if (!empty($value)) {
if (!isset($this->responseHeaders[$key])) {
$this->responseHeaders[$key] = $value;
} elseif (is_array($this->responseHeaders[$key])) {
$this->responseHeaders[$key] = array_merge($this->responseHeaders[$key], [$value]);
} else {
$this->responseHeaders[$key] = array_merge([$this->responseHeaders[$key]], [$value]);
}
}
}
return strlen($header);
}