wp-includes/atomlib.php:383$new_mapping function is_declared_content_ns($new_mapping) { foreach($this->content_ns_contexts as $context) { foreach($context as $mapping) { if($new_mapping == $mapping) { return true; } } } return false; }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/atomlib.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.