Hotfix geom graph combine take2

[aarograh]

This rewrites the GraphType combine method to account for several robustness issues.

[HendersonSC]

Overall good start...You already know about the debug statements so I will give you a chance to clear those up before commenting on them.

It looks like you have added some comments on how it all works, but the is large enough its hard to expand it and make sure it all flows. I will try to look at that in a little more detail on a second look.

[HendersonSC]

As far as comments and process go, it is clearly better. I don't know where you want to draw the line, someone just getting into graphs might not fully keep up, but I think generally between the naming and comments its in a decent place.

[aarograh]

Alright, I think this is all set if you want to give it a final look over @HendersonSC . The only test that failed is testGenReqTables, which has nothing to do with my changes. The docker container downloads a bunch of python packages each time it runs and we think that one of the packages got changed in a way that broke that test.

[aarograh]

the failed test is testGenReqTables due to python package changes and has nothing to do with these changes. Going ahead with the merge.