How to set KeyTip in the WPF Ribbon control?

<Syncfusion:Ribbon  Name="ribbon"  VerticalAlignment="Top">
    <Syncfusion:Ribbon.BackStage>
        <Syncfusion:Backstage Syncfusion:Ribbon.KeyTip="B">            <Syncfusion:BackstageTabItem Header="New" Syncfusion:Ribbon.KeyTip="N"/>
            <Syncfusion:BackstageTabItem Header="Print" Syncfusion:Ribbon.KeyTip="P"/>
            <Syncfusion:BackstageTabItem Header="Save As" Syncfusion:Ribbon.KeyTip="H">
                <Syncfusion:ApplicationMenuGroup Header="Save in another format" IconBarEnabled="False">
                    <Syncfusion:SimpleMenuButton Label="Save As" Description="save in your own format"/>
                </Syncfusion:ApplicationMenuGroup>
             </Syncfusion:BackstageTabItem>
             <Syncfusion:BackstageTabItem Header="Discard" Syncfusion:Ribbon.KeyTip="D"/>
              <Syncfusion:BackstageTabItem Header="Delete" Syncfusion:Ribbon.KeyTip="E"/>
              <Syncfusion:BackstageTabItem Header="Share" Syncfusion:Ribbon.KeyTip="S"/>
         </Syncfusion:Backstage>
     </Syncfusion:Ribbon.BackStage>
     <Syncfusion:RibbonTab Name="tab" Caption="Home" Syncfusion:Ribbon.KeyTip="H" >
         <Syncfusion:RibbonBar Header="Clipboard" Syncfusion:Ribbon.KeyTip="M"LauncherClick="OnLauncherClick" >
             <Syncfusion:SplitButton Label="Paste" SizeForm="Large" Syncfusion:Ribbon.KeyTip="V" LargeIcon="/Resources/Paste32.png" />
             <Syncfusion:RibbonButton  Label="Cut" SizeForm="ExtraSmall" Syncfusion:Ribbon.KeyTip="X" SmallIcon="/Resources/Cut16.png"  />
              <Syncfusion:RibbonButton  Label="Copy" SizeForm="ExtraSmall" Syncfusion:Ribbon.KeyTip="C"  SmallIcon="/Resources/Copy16.png"  />
              <Syncfusion:RibbonButton  Label="Format Painter" SizeForm="ExtraSmall" Syncfusion:Ribbon.KeyTip="Y" SmallIcon="/Resources/FormatPainter16.png"   />         </Syncfusion:RibbonBar>
         <Syncfusion:RibbonBar Header="BackStage Operations" LauncherClick="OnLauncherClick" Syncfusion:Ribbon.KeyTip="Z" >
              <Syncfusion:RibbonCheckBox Syncfusion:Ribbon.KeyTip="O" Content="Cancel BackStage Opening" x:Name="BackStageOpeningCheckBox"/>
              <Syncfusion:RibbonComboBox SelectedIndex="0" FlowDirection="LeftToRight" Width="110"  Syncfusion:Ribbon.KeyTip="F"  >
                  <Syncfusion:RibbonComboBoxItem Syncfusion:Ribbon.KeyTip="E">Email_Message</Syncfusion:RibbonComboBoxItem>
                  <Syncfusion:RibbonComboBoxItem Syncfusion:Ribbon.KeyTip="M">Meeting</Syncfusion:RibbonComboBoxItem>
                  <Syncfusion:RibbonComboBoxItem Syncfusion:Ribbon.KeyTip="A">Appointment</Syncfusion:RibbonComboBoxItem>
              </Syncfusion:RibbonComboBox>          </Syncfusion:RibbonBar>     </Syncfusion:RibbonTab>     <Syncfusion:RibbonTab Caption="Insert" Syncfusion:Ribbon.KeyTip="I" >     </Syncfusion:RibbonTab></Syncfusion:Ribbon>

Ribbon.SetKeyTip(tab, "H");