code: private final boolean checkUnderflowWithRight(final int slot) {
  		final Node<K, V> nodeLeft = tree.getNode(childs[slot]);
  		if (nodeLeft.isUnderFlow()) {
  			final Node<K, V> nodeRight = tree.getNode(childs[slot + 1]);
  			if (nodeLeft.canMerge(nodeRight)) {
  				nodeLeft.merge(this, slot, nodeRight);
  				childs[slot] = nodeLeft.id;
  			} else {
  				nodeLeft.shiftRL(this, slot, nodeRight);
  			}
  			//
  			// Update Changed Nodes
  			tree.putNode(this);
  			tree.putNode(nodeRight);
  			tree.putNode(nodeLeft);
  			return true;
  		}
  		return false;
  	}
docs: Check if underflow ocurred in child of slot
  
  @param nodeParent
  @param slot the index of a child in nodeParent