ENH: __pandas_priority__
Will allow dask/modin to address #38946 and https://github.com/modin-project/modin/issues/4646, respectively.

Also can be used to make non-masked EAs defer to masked EAs.
This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. @jbrockmendel I see there is no feedback from others here. But I guess we'll need documentation if we want to merge this. It should also help the discussion, I checked the referred issues, but it's not immediately clear how the new attribute works. @jbrockmendel Would there be a release note needed for this? Added a whatsnew, not sure how to make a reference to _extending.pandas_priority @jreback suggestions on how to get the whatsnew to point to the appropriate place in the docs? #@jbrockmendel no idea sorry > Added a whatsnew, not sure how to make a reference to _extending.pandas_priority

``` :ref:`See the developer guide <extending.pandas_priority>` ``` green Thanks @jbrockmendel 