docs: function (lineWidth, radius) {
  		var center = this.center;
  		radius = pick(radius, center[2] / 2 - this.offset);
  		
  		return this.chart.renderer.symbols.arc(
  			this.left + center[0],
  			this.top + center[1],
  			radius,
  			radius, 
  			{
  				start: this.startAngleRad,
  				end: this.endAngleRad,
  				open: true,
  				innerR: 0
  			}
  		);
  	}