wp-includes/class-wp-admin-bar.php:246array|null final protected function _get_nodes() { if ( $this->bound ) { return null; } return $this->nodes; }Introduced in 3.3.0. One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
array|void to array|null.verified against sourcesrc/wp-includes/class-wp-admin-bar.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.