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    [Parameter]
    public IEnumerable<object> DataSource {set; get; }

    private IEnumerable<object> Cache {set; get; } = null;
    List<MyColumn> Columns = new List<MyColumn>();
    public void AddColumn(MyColumn column)
    {
        var seg = DataSource;
        Cache ??= DataSource.ToList();
        DataSource = Cache;

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@page "/"
Tics per second: <input type="range" min="1" max="500" @bind="@CurrentValue" class="slider" id="myRange"> @CurrentValue
<br/><br/>
<div style="width:500px; height:10px; background-color: blue; position: relative;">
    <div class="ball" style="@position_txt"></div>
</div>
<br/><br/>
<span>@DateTime.Now.ToString("HH:mm:ss")</span>
<span>Number of renders: @nRenders.ToString("N0")</span>
<br/><br/>