For some reason, in ExtJS 6 I cannot do something that worked literally for years with previous versions of the library. I cannot add a new node to a selected one. This is the code I have:
// ^^^ this works. Nodes are added to the root
// ^^^ this does not work, even though "selected" is just an ordinary node
// with leaf = false
If I check "selected" node and "selected.firstChild", I see what I expect to see - just normal nodes:
console.log(selected); // <-- I see that it is indeed the node, I selected
console.log(selected.firstChild); // <-- it's ok.