code: func (f *Fpdf) Circle(x, y, r float64, styleStr string) {
  	f.Ellipse(x, y, r, r, 0, styleStr)
  }
docs: // Circle draws a circle centered on point (x, y) with radius r.
  //
  // styleStr can be "F" for filled, "D" for outlined only, or "DF" or "FD" for
  // outlined and filled. An empty string will be replaced with "D". Drawing uses
  // the current draw color and line width centered on the circle's perimeter.
  // Filling uses the current fill color.