Expander HeaderTemplate not working

[tedypranolo]

Expander has a HeaderTemplate, but I notice it is not actually applied to the ToggleButton.ContentTemplate that displays the header
Default theme

 <Style Selector="Expander[ExpandDirection=Down]">
    <Setter Property="Template">
      <ControlTemplate>
        <Border Background="{TemplateBinding Background}">
          <Grid RowDefinitions="Auto,*">
            <ToggleButton Name="PART_toggle" Grid.Row="0"  Content="{TemplateBinding Header}" IsChecked="{TemplateBinding IsExpanded, Mode=TwoWay}" />
            <ContentPresenter Name="PART_ContentPresenter"
                              Grid.Row="1"
                              IsVisible="{TemplateBinding IsExpanded}"
                              ContentTemplate="{TemplateBinding ContentTemplate}"
                              Content="{TemplateBinding Content}"
                              HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                              VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                              Padding="{TemplateBinding Padding}" />
          </Grid>
        </Border>
      </ControlTemplate>
    </Setter>
  </Style>

[SCLDGit]

Any progress on this?

[maxkatz6]

Can be easily fixed by adding missing content template, if somebody wants to contribute.

[Takoooooo]

I would like to clarify.It doesn't work only in simple theme