docs: function (angle, radius) {
  		
  		var chart = this.chart,
  			center = this.center;
  			
  		angle = this.startAngleRad + angle;
  
  		return {
  			x: chart.plotLeft + center[0] + Math.cos(angle) * radius,
  			y: chart.plotTop + center[1] + Math.sin(angle) * radius
  		}; 
  		
  	}