wp-includes/deprecated.php:3169Display "sticky" CSS class, if a post is sticky.
$post_idintoptionalnullfunction sticky_class( $post_id = null ) { _deprecated_function( __FUNCTION__, '3.5.0', 'post_class()' ); if ( is_sticky( $post_id ) ) echo ' sticky';}Introduced in 2.7.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/deprecated.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.