code: func (b *SparkChart) Draw() {
  	if b.hidden {
  		return
  	}
  
  	b.mtx.RLock()
  	defer b.mtx.RUnlock()
  
  	PushAttributes()
  	defer PopAttributes()
  
  	fg, bg := RealColor(b.fg, b.Style(), ColorSparkChartText), RealColor(b.bg, b.Style(), ColorSparkChartBack)
  	SetTextColor(fg)
  	SetBackColor(bg)
  	FillRect(b.x, b.y, b.width, b.height, ' ')
  
  	if len(b.data) == 0 {
  		return
  	}
  
  	b.drawValues()
  	b.drawBars()
  }
docs: // Repaint draws the control on its View surface