How to resize an MDI window to its child size in DocumentContainer?

//Code Explains how to resize an MDI window to its child size in DocumentContainer
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:syncfusion="http://schemas.syncfusion.com/wpf" x:Class="DocumentContainer_Size_.MainWindow"
Title="MainWindow" Height="350" Width="525">
<Grid>
<syncfusion:DocumentContainer Name="Document" Mode="MDI"   >
 <ContentControl Name="size1" syncfusion:DocumentContainer.Header="Resize1" Height="200" Width="300"  syncfusion:DocumentContainer.SizetoContentInMDI="True">
<FlowDocument>
<Paragraph>
A DocumentContainer is a control that is used for holding the documents, controls 
and panels.
</Paragraph>
</FlowDocument>
</ContentControl>
<ContentControl syncfusion:DocumentContainer.Header="Control" Height="200" Width="300" syncfusion:DocumentContainer.SizetoContentInMDI="True">
<FlowDocument>
<Paragraph>
  Document Container Test
</Paragraph>
</FlowDocument>
</ContentControl>
</syncfusion:DocumentContainer>
</Grid>
</Window>

//Code Explains how to resize an MDI window to its child size in DocumentContainer
namespace DocumentContainer_Size
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DocumentContainer.SetSizetoContentInMDI(size1,true);
}
}
}