I have a set of date that has been repeated several number of times.

I've managed to take the unique values from it using the below function.

```
var m = d3.nest()
            .key(function(d) { return d.Date; })
            .rollup(function(d) {return d.Date;})
            .entries(data);

```

Here's the data output.

```

    [
      {
        "key": "2014-01-01"
      },
      {
        "key": "2014-01-02"
      },
      {
        "key": "2014-01-03"
      },
      {
        "key": "2014-01-04"
      },
      {
        "key": "2014-01-05"
      },
      {
        "key": "2014-01-06"
      },
      {
        "key": "2014-01-07"
      },
      {
        "key": "2014-01-08"
      },
      {
        "key": "2014-01-09"
      },
      {
        "key": "2014-01-10"
      }

```

I wanted to amend that array something like this.

```

    ["2014-01-01", "2014-01-02", "2014-01-03", "2014-01-04", "2014-01-05"]

```

Any help will be very much thankful.