wp-includes/pomo/translations.php:107Sets translation headers.
$headersarray public function set_headers( $headers ) { foreach ( $headers as $header => $value ) { $this->set_header( $header, $value ); } }Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/pomo/translations.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.