code: func (f *Fpdf) GetMargins() (left, top, right, bottom float64) {
  	left = f.lMargin
  	top = f.tMargin
  	right = f.rMargin
  	bottom = f.bMargin
  	return
  }
docs: // GetMargins returns the left, top, right, and bottom margins. The first three
  // are set with the SetMargins() method. The bottom margin is set with the
  // SetAutoPageBreak() method.