wp-includes/class-wp-customize-manager.php:3973Registers a customize panel type.
$panelstring public function register_panel_type( $panel ) { $this->registered_panel_types[] = $panel; }Introduced in 4.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-customize-manager.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.