<Storyboard x:Name="OverlayOpenPane">
            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="SplitView" Storyboard.TargetProperty="Visibility">
                <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="Visible"/>
            </ObjectAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames Storyboard.TargetName="PaneTransform" Storyboard.TargetProperty="X">
                <DiscreteDoubleKeyFrame KeyTime="0:0:0" Value="{Binding Source={StaticResource SizeHelper}, Path=NegativePaneWidth}"/>
                <SplineDoubleKeyFrame KeyTime="0:0:0.5" KeySpline="0.1,0.9 0.2,1.0" Value="0"/>
            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
        <Storyboard x:Name="OverlayClosePane">
            <DoubleAnimationUsingKeyFrames Storyboard.TargetName="PaneTransform" Storyboard.TargetProperty="X">
                <DiscreteDoubleKeyFrame KeyTime="0:0:0" Value="0"/>
                <SplineDoubleKeyFrame KeyTime="0:0:0.417" KeySpline="0.66,0. 0.0,1.0" Value="{Binding Source={StaticResource SizeHelper}, Path=NegativePaneWidth}"/>
            </DoubleAnimationUsingKeyFrames>
            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="SplitView" Storyboard.TargetProperty="Visibility">
                <DiscreteObjectKeyFrame KeyTime="0:0:0" Value="Visible"/>
                <DiscreteObjectKeyFrame KeyTime="0:0:0.5" Value="Collapsed"/>
            </ObjectAnimationUsingKeyFrames>
        </Storyboard>