code: function($super, key, value, properties) {
              var angle;
              $super(key, value, properties);
              switch(key) {
  
                  case 'chart.rangeStartAngle':
                      angle = parseInt(value, 10);
                      if(!isNaN(angle)) {
                          // add 90 to startAngle because we start at south instead of east
                          this.startAngle = this.degToRad(angle + 90);
                      }
                      break;
                  case 'chart.rangeArcAngle':
                      angle = parseInt(value, 10);
                      if(!isNaN(angle)) {
                          this.arcAngle = this.degToRad(angle);
                      }
                      break;
                  default:
                      // no-op, ignore unsupported properties
                      break;
              }
          }
docs: override