An object of this class is used as a proxy for the authenticates_many
relationship. It basically allows you to "save" scope details and
call them on an object, which allows you to do the following:
@account.user_sessions.new
@account.user_sessions.find
# ... etc
You can call all of the class level methods off of an object with a saved
scope, so that calling the above methods scopes the user sessions down to
that specific account. To implement this via ActiveRecord do something
like:
class User < ActiveRecord::Base
authenticates_many :user_sessions
end