Inherits from DraggableBox.

A legend is a wibject that should be a child (does not have to be the direct child) of an axes. It displays a description for each line in the axes, and is draggable.

A Legend can be shown with the function vv.legend(), or using the Axes.legend property.

The Legend class implements the following methods:
SetStrings

Set the strings of the legend labels.