gitlab-org--gitlab-foss/app/mailers/emails/groups.rb

module Emails
  module Groups
    def group_access_granted_email(user_group_id)
      @membership = UsersGroup.find(user_group_id)
      @group = @membership.group

      mail(to: @membership.user.email,
           subject: subject("Access to group was granted"))
    end
  end
end