wp-includes/php-ai-client/src/Providers/Http/Collections/HeadersCollection.php:86Checks if a header exists.
$namestringbool public function has(string $name): bool { return isset($this->headersMap[strtolower($name)]); }Introduced in 0.1.0. Unchanged from 7.0.4 through 7.1.0.
Signature, return type and hooks compared across 2 parsed releases.
src/wp-includes/php-ai-client/src/Providers/Http/Collections/HeadersCollection.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.