code: func (f *Fpdf) Link(x, y, w, h float64, link int) {
  	f.newLink(x, y, w, h, link, "")
  }
docs: // Link puts a link on a rectangular area of the page. Text or image links are
  // generally put via Cell(), Write() or Image(), but this method can be useful
  // for instance to define a clickable area inside an image. link is the value
  // returned by AddLink().