REF: collect to_xarray tests
I'm split on where to put test_to_xarray.  Since its testing one method, tests/generic/methods/ makes sense.  BUT we could try to reserve that directory for tests that are nicely parametrized over Series/DataFrame, which these are not.  Thoughts?
I would create pandas/tests/downstream and move pandas/tests/test_downstream.py to there along with this test file (name is good), maybe even move the xarray test to that (inside test_downstream.py) ping on green. > I would create pandas/tests/downstream and move pandas/tests/test_downstream.py to there along with this test file (name is good), maybe even move the xarray test to that (inside test_downstream.py)

I'll give this some thought.  I kind of like test_downstream.py for the specific "dont break downstream" purpose it has no (just asked xarray folks to open a PR with a regression test thatll go there) hmm needs a rebase thanks