user-switching.php
public static function get_old_user() {
		$cookie = user_switching_get_olduser_cookie();
		if ( ! empty( $cookie ) ) {
			$old_user_id = wp_validate_auth_cookie( $cookie, 'logged_in' );

			if ( $old_user_id ) {
				return get_userdata( $old_user_id );
			}
		}
		return false;
	}
public static function get_old_user() {
		$cookie = user_switching_get_olduser_cookie();
		if ( ! empty( $cookie ) ) {
			$old_user_id = wp_validate_auth_cookie( $cookie, 'logged_in' );

			if ( $old_user_id ) {
				return get_userdata( $old_user_id );
			}
		}
		return false;
	}
public static function get_old_user ( ) { $ cookie = user_switching_get_olduser_cookie ( ) ; if ( ! empty ( $ cookie ) ) { $ old_user_id = wp_validate_auth_cookie ( $ cookie , 'logged_in' ) ; if ( $ old_user_id ) { return get_userdata ( $ old_user_id ) ; } } return false ; }
Validates the old user cookie and returns its user data.

@return false|WP_User False if there's no old user cookie or it's invalid, WP_User object if it's present and valid.
Validates the old user cookie and returns its user data .