Stretch Problem

This is a Vertical Layout Panel, the node width now upon the max width green block.
My problem is that i idk how to strech these three green blocks…
if i set them all ‘go.GraphObject.Horizontal’, they will all dont stretch but suit the min size.
if i set two width smaller blocks ‘go.GraphObject.Horizontal’ and max one set nothing it’s will go right, does it make any sense, i dont really get the way it works.
Anyway, this problem brother me all day and i need some help.
Code Brief:

Is there a function i can compute texts width.~

You might need to stretch the contents of those stretched panels.

noop, it’s doesnt work even though i set every ‘go.GraphObject.Horizontal’.
it’s seem like go.TextBlock doesnt stretch itself.
i’m afraid the only solution is calculate the max width and set to go.Node