function create(sShape) {
		switch (sShape) {
			case 'rect':
				return new Rect().createShape(SVG_NAMESPACE, sShape);
			case 'poly':
				return new Polygon().createShape(SVG_NAMESPACE, "polygon");
			case 'circle':
				return new Circle().createShape(SVG_NAMESPACE, sShape);
			default:
		}
	}
Return new Shape (Rect, Polygon, Circle) instance from given shape type
@param sShape {string} shape type
@return {Shape} (Rect, Polygon, Circle)