protected Nodo pai(Nodo nodoRoot, int key){  
        if(nodoRoot == null){
            return null;
        }
        else{
            Nodo nodoLeft = nodoRoot.getLeft();
            Nodo nodoRight = nodoRoot.getRight();
           if((nodoLeft != null && key == nodoLeft.getKey()) || (nodoRight != null && key == nodoRight.getKey())){
               return nodoRoot;
           }
           else if(key < nodoRoot.getKey()){
               return pai(nodoRoot.getLeft(), key);
           }
           else{
               return pai(nodoRoot.getRight(), key);
           }
        }
    }