Migra doc Table cell with Chart

Question

bellow is my code for table with cell chart

Table innerTable = new();
innerTable.AddColumn(200);
innerTable.AddColumn(200);
innerTable.LeftPadding = 0;
innerTable.RightPadding = 0;

var lastRow = innerTable.AddRow();
lastRow.Format.SpaceAfter = 5;

var secondRowCell1 = innerTable[0, 0];
secondRowCell1.Format.LeftIndent = 5;
secondRowCell1.AddParagraph("test");

var secondRowCell2 = innerTable[0, 1];
secondRowCell2.Format.RightIndent = 5;
secondRowCell2.Elements.Add(GetChart());

My definition for chart, which i using for cell

Chart chart = new Chart
{
 Left = 0,
 Width = 150,
Height = 150
};

Series series = chart.SeriesCollection.AddSeries();
series.ChartType = ChartType.Line;
series.Add(new double[] { 41, 7, 5, 45, 13, 10, 21, 13, 18, 9 });

return chart;

My problem, cell chart doesnt have border, same cell with AddParagraph working fine and show border. Can you help me?

Border on cell with paragraph