code: public void curveTo(float x1, float y1, float x2, float y2, float x3, float y3) {
          content.append(x1).append(' ').append(y1).append(' ').append(x2).append(' ').append(y2).append(' ').append(x3).append(' ').append(y3).append(" c").append_i(separator);
      }
docs: Appends a B&#xea;zier curve to the path, starting from the current point.
  
  @param       x1      x-coordinate of the first control point
  @param       y1      y-coordinate of the first control point
  @param       x2      x-coordinate of the second control point
  @param       y2      y-coordinate of the second control point
  @param       x3      x-coordinate of the ending point (= new current point)
  @param       y3      y-coordinate of the ending point (= new current point)