wp-includes/ms-load.php:546This deprecated function managed much of the site and network loading in multisite.
WP_Networkfunction wpmu_current_site() { global $current_site; _deprecated_function( __FUNCTION__, '3.9.0' ); return $current_site;}Introduced in 3.0.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/ms-load.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.