code: @Override
      protected boolean prepare(final Context2D context, final Attributes attr, final double alpha)
      {
          final double r = attr.getRadius();
  
          final double beg = attr.getStartAngle();
  
          final double end = attr.getEndAngle();
  
          if (r > 0)
          {
              context.beginPath();
  
              if (beg == end)
              {
                  context.arc(0, 0, r, 0, Math.PI * 2, true);
              }
              else
              {
                  context.arc(0, 0, r, beg, end, attr.isCounterClockwise());
              }
              context.closePath();
  
              return true;
          }
          return false;
      }
docs: Draws this chord.
  
  @param context