Function selectButton

test/jasmine/tests/updatemenus_test.js:904–910

(buttonIndex, opts)

    }

    function selectButton(buttonIndex, opts) {
        opts = opts || {};
        var k = opts.type === 'buttons' ? 'buttonClassName' : 'dropdownButtonClassName';
        var buttons = d3SelectAll('.' + constants[k]);
        var button = d3Select(buttons[0][buttonIndex]);
        return button;
    }
});