code: func DrawHorizontalLine(x, y, w int, r rune) {
  	x, y, w, _ = clip(x, y, w, 1)
  	if w == 0 {
  		return
  	}
  
  	for i := x; i < x+w; i++ {
  		putCharUnsafe(i, y, r)
  	}
  }
docs: // DrawHorizontalLine draws the part of the horizontal line that is inside
  // current clipping rectangle