The Service Tree Model

<UserControl x:Class="ServiceTreeSample.Views.TabbedDocumentView"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <TabControl ItemsSource="{Binding Documents}">
        <TabControl.ItemContainerStyle>
            <Style TargetType="TabItem">
                <Setter Property="IsSelected" Value="{Binding IsActive}"/>
                <Setter Property="HeaderTemplate">
                    <Setter.Value>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="{Binding Document.Title}"/>
                                <TextBlock Text="*" Margin="3,0">
                                    <TextBlock.Style>
                                        <Style TargetType="TextBlock">
                                            <Style.Triggers>
                                                <DataTrigger Binding="{Binding Document.IsModified}" Value="False">
                                                    <Setter Property="Visibility" Value="Collapsed"/>
                                                </DataTrigger>
                                            </Style.Triggers>
                                        </Style>
                                    </TextBlock.Style>
                                </TextBlock>
                                <Button Command="{Binding CloseCommand}">
                                    <Button.Template>
                                        <ControlTemplate TargetType="Button">
                                            <Grid Margin="3,0,0,0">
                                                <Ellipse Width="12" Height="12" Fill="DarkRed"/>
                                                <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="×" Foreground="White"
                                                           Margin="0,-2,0,0"/>
                                            </Grid>
                                        </ControlTemplate>
                                    </Button.Template>
                                </Button>
                            </StackPanel>
                        </DataTemplate>
                    </Setter.Value>
                </Setter>
                <Setter Property="Content" Value="{Binding View}"/>
            </Style>
        </TabControl.ItemContainerStyle>
        
    </TabControl>
</UserControl>