Terry,

I'm not sure if I phrased my initial question correctly.  I've made a pull request to show you what I was thinking.

What I had tried to show with the test case change is that, prior to the guarantee of insertion order on the dictionary, the check `eq(tcl, [C0, f0])` would have failed without the sort because `transform_children` would have returned `[f0, C0]`.  With the sort in place or with the guarantee insertion order, this test doesn't fail.

Thanks!