relation() helper is backwards

[stub42]

d.sentry['foo'][0].relation(from_rel, to_rel) returns relation data 'from the remote unit'. This isn't helpful, as there might be multiple remote units (the to_rel end). If it returned the local data (the from_rel end), it would be useful for testing scaled applications since there is only a single unit involved.

I don't think this can be fixed without breaking backwards compatibility or introducing new methods :-(

[stub42]

Testing shows that it is returning relation data from the local unit, which is I think the correct behaviour. So this is a documentation issue, or an issue with my reading of the documentation. Correct wording seems very tricky here.