private function filterHeaders(array $originalHeaders)
{
$headerNames = $headers = [];
foreach ($originalHeaders as $header => $value) {
if (!is_string($header)) {
continue;
}
if (!is_array($value) && !is_string($value)) {
continue;
}
if (!is_array($value)) {
$value = [$value];
}
$headerNames[strtolower($header)] = $header;
$headers[$header] = $value;
}
return [$headerNames, $headers];
}