Lua A bar graph

[lexus21]

I would like to make a chart with 30 bars side by side. Each bar with a width of say 2px and a value 20px I have the following code:

function initBars()
  local VisualizationContainer = VWindow:recursiveGetChildById('VisualizationContainer')
  for i = 1, 30 do
    local bar = g_ui.createWidget('UIWidget', VisualizationContainer)
    bar:setBackgroundColor('#CC99FF')
    bar:setHeight(20)
    bar:setWidth(2) 
    table.insert(bars, bar)
  end
end

and otui:

MiniWindow
  id: VWindow
  !text: tr('Chart')
  height: 190
  icon: /images/topButtons/inventory
  @onClose: modules.game_chart.onMiniWindowClose()
  &save: true
  &autoOpen: 11

  MiniWindowContents
    padding-left: 5
    padding-right: 5
    layout: verticalBox
     
    UIWidget
      id: VisualizationContainer
      height: 100
      margin-top: 5
      background-color: #FFFF00

only one bar is shown on the chart.

I'm using otcv8.

Question: How can I make 30 bars side by side on a chart?