code: func SetCell(x, y int, ch rune, fg, bg Attribute) {
  	if x < 0 || x >= back_buffer.width {
  		return
  	}
  	if y < 0 || y >= back_buffer.height {
  		return
  	}
  
  	back_buffer.cells[y*back_buffer.width+x] = Cell{ch, fg, bg}
  }
docs: // Changes cell's parameters in the internal back buffer at the specified
  // position.