public void poistaPieni() {
        if (tyhja()) {
            return;
        }
        boolean jarjVaihtoOk = false;
        BinomiNode prev = null;
        BinomiNode prevMin = null;
        BinomiNode current = root;
        BinomiNode currentMin = root;
        BinomiKeko keko;
        while (current != null) {
            if (current.arvo < currentMin.arvo) {
                currentMin = current;
                prevMin = prev;
            }
            prev = current;
            current = current.sisar;
        }
        
        if (prevMin == null) {
            root = root.sisar;
        }
        else {
            prevMin.sisar = currentMin.sisar;
        }
        
        if (currentMin.lapsi != null) {
            prev = null;
            current = currentMin.lapsi;
            BinomiNode next = currentMin.lapsi.sisar;
            while (next != null) {
                current.sisar = prev;
                prev = current;
                current = next;
                next = current.sisar;
            }
            current.sisar = prev;
            jarjVaihtoOk = true;
        }
        if (jarjVaihtoOk) {
            keko = new BinomiKeko(1, current);
        }
        else {
            keko = new BinomiKeko(0, null);
        }
        
        current = keko.root;
        while (current != null) {
            current.parent = null;
            current = current.sisar;
        }
        
        keko = union(this, keko);
        root = keko.root;
        keonKoko--;
    }