mongoid/mongoid — pull request #3364 by mattconnolly (2013-11-05 04:12:50+00:00)
Title: Add field option :only_alias to skip destructive methods for the primary name.

The idea of this is that protected field names, such as :metadata
can be accessed via their aliases but the accessors for the protected
name are skipped, allowing access to these protected fields via the
alias.

See closed issue #3362.