WPF Control Composition (Part 1 of 2)

<UserControl x:Class="SimpleControls.ComboBox.ComboBoxWithLabel"
             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="100"
             d:DesignWidth="453"

             xmlns:local="clr-namespace:SimpleControls.ComboBox"
             >
  <Grid>
    <Grid.RowDefinitions>
      <RowDefinition Height="Auto"/>
      <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
      <!-- This will bind the Content property on the label to the 'LabelContent' property on this control-->
    <Label Content="{Binding Path=LabelContent, RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}}" 
                     HorizontalAlignment="Left" VerticalAlignment="Bottom" Grid.Row="0"/>

      <!-- This will bind the ItemsSource of the ComboBox to this control's ItemsSource property -->
    <ComboBox ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}, Path=ItemsSource}"
              DisplayMemberPath="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}, Path=DisplayMemberPath}"
              SelectedValuePath="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}, Path=SelectedValuePath}"
              SelectedValue="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}, Path=SelectedValue}"
              SelectedItem="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}, Path=SelectedItem}"
              SelectedIndex="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=local:ComboBoxWithLabel, AncestorLevel=1}, Path=SelectedIndex}"
              VerticalAlignment="Top" HorizontalAlignment="Stretch"
              Grid.Row="1">
      </ComboBox>
  </Grid>
</UserControl>