GooCanvasPolyline represents a polyline item, which is a series of one or more lines, with optional arrows at either end.
It is a subclass of CanvasItemSimple and so inherits all of the style properties such as "stroke-color", "fill-color" and "line-width".
It also implements the CanvasItem interface, so you can use the CanvasItem functions such as raise and rotate.
To create a CanvasPolyline use create, or create_line for a simple line between two points.
To get or set the properties of an existing CanvasPolyline, use @get and @set.