rails/rails — pull request #18214 by kubum (2014-12-26 20:49:48+00:00)
Title: Remove unused 'model' attribute in Association initializer

Since support for 'activerecord-deprecated_finders' was dropped, `model` attribute became obsolete and could be safely removed. Please feel free to correct me if I am mistaken.

Also, by already existed comment guidance `valid_options` was moved to a constant.