Optimisation hook for array/bag/dataframe

[multimeric]

I just realised that the current hook that we use to insert graphchain into dask is delayed_optimize, which only actually applies for "raw" Delayed instances, but doesn't actually apply to e.g. the DataFrame API, which is a very popular part of dask. As described here, these types have their own optimisation hooks that we would need to implement. I will look in to writing one for the DataFrame API. I think we should be able to integrate it fairly easily into the current codebase.

• [ ] array_optimize
• [ ] dataframe_optimize
• [ ] bag_optimize

[lsorber]

That would be great, thank you @multimeric!

[multimeric]

Okay so upon investigation, it seems that all the hooks use the same API, so we're all good in that regard, and it was just an unrelated bug that I was hitting.