private function isVarModification($stmt)
    {
        return $stmt instanceof Expr\PostDec ||
        $stmt instanceof Expr\PostInc ||
        $stmt instanceof Expr\PreDec ||
        $stmt instanceof Expr\PreInc;
    }
private function isVarModification($stmt)
    {
        return $stmt instanceof Expr\PostDec ||
        $stmt instanceof Expr\PostInc ||
        $stmt instanceof Expr\PreDec ||
        $stmt instanceof Expr\PreInc;
    }
@param mixed $stmt

@return bool