private void AddToTree(BcsExpressionNode node, MenuItem item)
{
//ISSUE: make dedicated function for errors
foreach (var error in node.Errors)
{
item.NodeErrors.Add(error.Message);
}
var parentItem = NodeCache[node.ParentNode.UniqueId];
parentItem.Items.Add(item);
NodeCache.Add(node.UniqueId, item);
}