Is it possible to add a method to an array() in javascript? (I know about prototypes, but I don't want to add a method to every array, just one in particular).

The reason I want to do this is because I have the following code

function drawChart()
{
    //...
    return [list of important vars]
}

function updateChart(importantVars)
{
    //...
}

var importantVars = drawChart();

updateChart(importantVars);

And I want to be able to do something like this instead:

var chart = drawChart();<br>
chart.redraw();

I was hoping there was a way I could just attach a method to what i'm returning in drawChart(). Any way to do that?