def test_iadd(self, evt):
        rval = event.ReturnValue(append_events=[evt])
        rval2 = event.ReturnValue(eat=True, append_events=[evt])
        rset = event.ResultSet()

        rset += rval
        rset += rval2
        rset += None
        assert rset.eat
        assert rset.append_events == [evt, evt]
def edit_category(category_id):
    category = Category.query.filter_by(id=category_id).first_or_404()

    form = CategoryForm(obj=category)

    if form.validate_on_submit():
        form.populate_obj(category)
        flash(_("Category updated."), "success")
        category.save()

    return render_template("management/category_form.html", form=form,
                           title=_("Edit Category"))