Pass Repo to run_batch

[cspeper]

To rotate requests among read replicas, the custom run_batch needs to be passed the repo set in the dataloader

[benwilson512]

Hi @cspeper This is an interesting idea but it can't be used as is. This would be a breaking change as everyone's existing functions would fail.

Please reopen when there are:

1) Correct formatting so that the CI can run 2) Tests 3) Correct handling for both 6 and 7 arity run_batch clauses.