private function emailToUsername($email = null)
    {
        if ($user = get_user_by('email', $email)) {
            if (isset($user->user_login)) {
                return $user->user_login;
            }
        }

        return null;
    }
private function emailToUsername($email = null)
    {
        if ($user = get_user_by('email', $email)) {
            if (isset($user->user_login)) {
                return $user->user_login;
            }
        }

        return null;
    }
private function emailToUsername ( $ email = null ) { if ( $ user = get_user_by ( 'email' , $ email ) ) { if ( isset ( $ user -> user_login ) ) { return $ user -> user_login ; } } return null ; }
Translate email to username
@return void
Translate email to username