wp-includes/class-wp-customize-manager.php:2028Prevents sending a 404 status when returning the response for the customize preview, since it causes the jQuery Ajax to fail. Send 200 instead.
public function customize_preview_override_404_status() { _deprecated_function( __METHOD__, '4.7.0' ); }Introduced in 4.0.0. 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.