pragmaticaly expand a node

hello

For example in the given example
http://khan4019.github.io/tree-grid-directive/test/treeGrid.html

i want to pragmatically expand only one given node (with his id or name) and collapse all other, for example expand "new york". how to do this please ?

in document there is "expand-to" but i don't understand how to use it. i have a rootscope but what i should but inside ?




