code: func (v *ViewPort) SetContent(x, y int, ch rune, comb []rune, s tcell.Style) {
  	if v.v == nil {
  		return
  	}
  	if x > v.limx && !v.locked {
  		v.limx = x
  	}
  	if y > v.limy && !v.locked {
  		v.limy = y
  	}
  	if x < v.viewx || y < v.viewy {
  		return
  	}
  	if x >= (v.viewx + v.width) {
  		return
  	}
  	if y >= (v.viewy + v.height) {
  		return
  	}
  	v.v.SetContent(x-v.viewx+v.physx, y-v.viewy+v.physy, ch, comb, s)
  }
docs: // SetContent is used to place data at the given cell location.  Note that
  // since the ViewPort doesn't retain this data, if the location is outside
  // of the visible area, it is simply discarded.
  //
  // Generally, this is called during the Draw() phase by the object that
  // represents the content.