orbit-basic/vendor/built_in_modules/personal_journal/app/models/journal_co_author_relation.rb

class JournalCoAuthorRelation
  include Mongoid::Document
  include Mongoid::Timestamps

  field :relation, localize: true

  has_and_belongs_to_many :journal_co_authors

  validates :relation, presence: true,
            uniqueness: { case_sensitive: false }
end