constructor([stroke], [background], [opacity], [x], [y], [_points])

Creates an instance of Polygon shape object.

Name	Type	Default	Description
`[stroke]`	Stroke	null	A border of the shape.
`[background]`	string	null	Color, gradient, or image background, similar to CSS. Use an empty string to remove the background.
`[opacity]`	number	1	Opacity of the shape (0 to 1).
`[x]`	number	0	Horizontal position from the left edge.
`[y]`	number	0	Vertical position from the top edge.
`[_points]`	Array.<object>	[]	An array of point objects that represent each corner of the shape [{x:number,y:number}, ...]. For example a simple start has 10 points.