def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def edit_forum(forum_id):
    forum = Forum.query.filter_by(id=forum_id).first_or_404()

    form = EditForumForm(forum)
    if form.validate_on_submit():
        form.save()
        flash(_("Forum updated."), "success")
        return redirect(url_for("management.edit_forum", forum_id=forum.id))
    else:
        if forum.moderators:
            form.moderators.data = ",".join([
                user.username for user in forum.moderators
            ])
        else:
            form.moderators.data = None

    return render_template("management/forum_form.html", form=form,
                           title=_("Edit Forum"))