XamlWriter skips “x:Name” attribute while saving ResourceDictionary

Here's custom style:

<Style TargetType="{x:Type Button}"><Setter Property="Focusable" Value="false" /><Setter Property="Background" Value="{StaticResource AppBackBrush}"/><Setter Property="Foreground" Value="{StaticResource AppBrush}"/><Setter Property="Template"><Setter.Value><ControlTemplate TargetType="Button"><Border BorderBrush="{StaticResource AppBrush}"
                            Name="content"
                            BorderThickness="1"
                            CornerRadius="3"
                            Background="{StaticResource AppBackBrush}"><Grid Background="Transparent"><Label Content="{TemplateBinding Content}"
                                   HorizontalContentAlignment="Center"
                                   VerticalContentAlignment="Center"
                                   Grid.Row="0" Grid.Column="0"
                                   Background="Transparent"
                                   Style="{x:Null}"
                                   Foreground="{TemplateBinding Foreground}"
                                   Padding="{TemplateBinding Padding}"/></Grid><Border.RenderTransform><!-- push the content a bit to the left and the top --><TranslateTransform x:Name="translation"
                                                X="-1" Y="-1"/></Border.RenderTransform></Border><ControlTemplate.Triggers><Trigger Property="IsPressed" Value="True"><Trigger.EnterActions><BeginStoryboard><Storyboard><DoubleAnimation Duration="0:0:0"
                                                         To="0"
                                                         Storyboard.TargetName="translation"
                                                         Storyboard.TargetProperty="(TranslateTransform.X)"/><DoubleAnimation Duration="0:0:0"
                                                         To="0"
                                                         Storyboard.TargetName="translation"
                                                         Storyboard.TargetProperty="(TranslateTransform.Y)"/></Storyboard></BeginStoryboard></Trigger.EnterActions><Trigger.ExitActions><BeginStoryboard><Storyboard><DoubleAnimation Duration="0:0:0"
                                                         To="-1"
                                                         Storyboard.TargetName="translation"
                                                         Storyboard.TargetProperty="(TranslateTransform.X)"/><DoubleAnimation Duration="0:0:0"
                                                         To="-1"
                                                         Storyboard.TargetName="translation"
                                                         Storyboard.TargetProperty="(TranslateTransform.Y)"/></Storyboard></BeginStoryboard></Trigger.ExitActions></Trigger><Trigger Property="IsEnabled" Value="False"><Setter TargetName="content" Property="Opacity" Value="0.5" /></Trigger></ControlTemplate.Triggers></ControlTemplate></Setter.Value></Setter></Style>

I save this ResourceDictionary that contains this style to string like this:

    XamlWriter.Save(s);

where s is ResourceDictionary. The problem is that when I get expected string, it looks so:

<Style TargetType=\"Button\" x:Key=\"{x:Type Button}\"><Style.Resources><ResourceDictionary /></Style.Resources><Setter Property=\"UIElement.Focusable\"><Setter.Value><s:Boolean>False</s:Boolean></Setter.Value></Setter><Setter Property=\"Panel.Background\"><Setter.Value><SolidColorBrush>#FFF1F2F4</SolidColorBrush></Setter.Value></Setter><Setter Property=\"TextElement.Foreground\"><Setter.Value><SolidColorBrush>#FF13776A</SolidColorBrush></Setter.Value></Setter><Setter Property=\"Control.Template\"><Setter.Value><ControlTemplate TargetType=\"Button\"><Border BorderThickness=\"1,1,1,1\" CornerRadius=\"3,3,3,3\" BorderBrush=\"#FF13776A\" Background=\"#FFF1F2F4\" Name=\"content\"><Border.RenderTransform><TranslateTransform X=\"-1\" Y=\"-1\" /></Border.RenderTransform><Grid><Grid.Style><Style TargetType=\"Grid\"><Style.Resources><ResourceDictionary /></Style.Resources><Setter Property=\"Panel.Background\"><Setter.Value><SolidColorBrush>#00FFFFFF</SolidColorBrush></Setter.Value></Setter></Style></Grid.Style><Label Content=\"{TemplateBinding ContentControl.Content}\" Background=\"#00FFFFFF\" Foreground=\"{TemplateBinding TextElement.Foreground}\" HorizontalContentAlignment=\"Center\" VerticalContentAlignment=\"Center\" Padding=\"{TemplateBinding Control.Padding}\" Style=\"{x:Null}\" Grid.Column=\"0\" Grid.Row=\"0\" /></Grid></Border><ControlTemplate.Triggers><Trigger Property=\"ButtonBase.IsPressed\"><Trigger.EnterActions><BeginStoryboard><Storyboard><Storyboard.Children><DoubleAnimation To=\"0\" Duration=\"00:00:00\" Storyboard.TargetName=\"translation\" Storyboard.TargetProperty=\"(TranslateTransform.X)\" /><DoubleAnimation To=\"0\" Duration=\"00:00:00\" Storyboard.TargetName=\"translation\" Storyboard.TargetProperty=\"(TranslateTransform.Y)\" /></Storyboard.Children></Storyboard></BeginStoryboard></Trigger.EnterActions><Trigger.ExitActions><BeginStoryboard><Storyboard><Storyboard.Children><DoubleAnimation To=\"-1\" Duration=\"00:00:00\" Storyboard.TargetName=\"translation\" Storyboard.TargetProperty=\"(TranslateTransform.X)\" /><DoubleAnimation To=\"-1\" Duration=\"00:00:00\" Storyboard.TargetName=\"translation\" Storyboard.TargetProperty=\"(TranslateTransform.Y)\" /></Storyboard.Children></Storyboard></BeginStoryboard></Trigger.ExitActions><Trigger.Value><s:Boolean>True</s:Boolean></Trigger.Value></Trigger><Trigger Property=\"UIElement.IsEnabled\"><Setter Property=\"UIElement.Opacity\" TargetName=\"content\"><Setter.Value><s:Double>0.5</s:Double></Setter.Value></Setter><Trigger.Value><s:Boolean>False</s:Boolean></Trigger.Value></Trigger></ControlTemplate.Triggers></ControlTemplate></Setter.Value></Setter></Style>

Please take a look at TranslateTransform in Border.RenderTransform. In the ResourceDictionary it has x:Name="translation", but the name is missing in the output string. 

Where was I mistaken or is this a bug? Thanks in advance.