src/System/Input.php
public static function getAuthUsername()
    {
        $result = null;
        if (isset($_SERVER['PHP_AUTH_USER'])) {
            $result = $_SERVER['PHP_AUTH_USER'];
        }
        if (trim($result) == '') {
            $result = null;
        }
        return $result;
    }
public static function getAuthUsername()
    {
        $result = null;
        if (isset($_SERVER['PHP_AUTH_USER'])) {
            $result = $_SERVER['PHP_AUTH_USER'];
        }
        if (trim($result) == '') {
            $result = null;
        }
        return $result;
    }
Get auth username.

@return string|null