A tooltip shows more information about an item on a page when the user hovers over that item. There are several ways to add a tooltip to a visualization, this challenge uses the SVG `title` element.
`title` pairs with the `text()` method to dynamically add data to the bars.
# --instructions--
Append a `title` element under each `rect` node. Then call the `text()` method with a callback function so the text displays the data value.
# --hints--
Your code should have 9 `title` elements.
```js
assert($('title').length == 9);
```
The first `title` element should have tooltip text of `12`.
```js
assert($('title').eq(0).text() == '12');
```
The second `title` element should have tooltip text of `31`.
```js
assert($('title').eq(1).text() == '31');
```
The third `title` element should have tooltip text of `22`.
```js
assert($('title').eq(2).text() == '22');
```
The fourth `title` element should have tooltip text of `17`.
```js
assert($('title').eq(3).text() == '17');
```
The fifth `title` element should have tooltip text of `25`.
```js
assert($('title').eq(4).text() == '25');
```
The sixth `title` element should have tooltip text of `18`.
```js
assert($('title').eq(5).text() == '18');
```
The seventh `title` element should have tooltip text of `29`.
```js
assert($('title').eq(6).text() == '29');
```
The eighth `title` element should have tooltip text of `14`.
```js
assert($('title').eq(7).text() == '14');
```
The ninth `title` element should have tooltip text of `9`.
