wp-includes/class-wp-theme-json-resolver.php:686Returns the ID of the custom post type that stores user data.
integer|null public static function get_user_global_styles_post_id() { if ( null !== static::$user_custom_post_type_id ) { return static::$user_custom_post_type_id; } $user_cpt = static::get_user_data_from_wp_global_styles( wp_get_theme(), true ); if ( array_key_exists( 'ID', $user_cpt ) ) { static::$user_custom_post_type_id = $user_cpt['ID']; } return static::$user_custom_post_type_id; }Introduced in 5.9.0. One change between 6.7.7 and 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
integer|null to int|null.verified against sourcesrc/wp-includes/class-wp-theme-json-resolver.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.