Override MetroTabItem controltemplate with close button

[Dimigergo]

Hello!

When I override the MetroTabItem controltemplate the close button doesn't works.

I have the following code:

<ControlTemplate x:Key="MainTabItem" TargetType="{x:Type mahapps:MetroTabItem}">
    <Border x:Name="Border"
            Margin="{TemplateBinding Padding}"
            BorderThickness="{TemplateBinding BorderThickness}"
            BorderBrush="{TemplateBinding BorderBrush}"
            Background="{TemplateBinding Background}"
            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}">
        <StackPanel Orientation="Horizontal">
            <Ellipse VerticalAlignment="Top" Width="8" Height="8" 
                        Margin="0,5,2,0"
                        Visibility="{TemplateBinding helpers:CControlsHelper.LogTabItemType, Converter={StaticResource logTypeVisibilityConverter}}"
                        Fill="{TemplateBinding helpers:CControlsHelper.LogTabItemType, Converter={StaticResource logTypeFillConverter}}" />
            <ContentPresenter x:Name="ContentSite"
                                Margin="2,1,2,1"
                                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                                VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                                TextElement.FontSize="{TemplateBinding mahapps:ControlsHelper.HeaderFontSize}"
                                TextElement.FontStretch="{TemplateBinding mahapps:ControlsHelper.HeaderFontStretch}"
                                TextElement.FontWeight="{TemplateBinding mahapps:ControlsHelper.HeaderFontWeight}"
                                TextElement.Foreground="{TemplateBinding Foreground}"
                                ContentSource="Header"
                                RecognizesAccessKey="True" />
            <TextBlock Text="{Binding Path=Tag, RelativeSource={RelativeSource TemplatedParent}, Converter={StaticResource keyConverter}}" 
                        Foreground="{TemplateBinding helpers:CControlsHelper.TagColor}"
                        VerticalAlignment="Top" 
                        HorizontalAlignment="Right"
                        Margin="2,0,5,0"/>
            <Grid HorizontalAlignment="Right">
                <Button x:Name="PART_CloseButton"
                        Style="{DynamicResource ChromelessButtonStyle}"
                        Background="{DynamicResource GrayNormalBrush}"
                        Width="{TemplateBinding mahapps:ControlsHelper.HeaderFontSize, Converter={StaticResource MetroTabItemCloseButtonWidthConverter}}"
                        Height="{Binding RelativeSource={RelativeSource Self}, Path=Width, Mode=OneWay}"
                        VerticalAlignment="Top"
                        IsTabStop="False"
                        Command="{TemplateBinding CloseTabCommand}"
                        CommandParameter="{TemplateBinding CloseTabCommandParameter}">
                    <Button.OpacityMask>
                        <VisualBrush Stretch="Uniform" 
                                        Visual="{StaticResource iconX}" />
                    </Button.OpacityMask>
                </Button>

                <Button Style="{DynamicResource ChromelessButtonStyle}"
                        Visibility="{TemplateBinding helpers:CControlsHelper.Watched, Converter={StaticResource boolToVisibilityConverter}}"
                        Background="{DynamicResource GrayNormalBrush}"
                        Width="{TemplateBinding mahapps:ControlsHelper.HeaderFontSize, Converter={StaticResource MetroTabItemCloseButtonWidthConverter}}"
                        Height="{Binding RelativeSource={RelativeSource Self}, Path=Width, Mode=OneWay}"
                        VerticalAlignment="Bottom"
                        IsTabStop="False">
                    <Button.OpacityMask>
                        <VisualBrush Stretch="Uniform" 
                                        Visual="{StaticResource iconRefresh}" />
                    </Button.OpacityMask>
                </Button>
            </Grid>
            <Rectangle Width="1" VerticalAlignment="Stretch" Margin="10,5,0,0" Stroke="{DynamicResource AccentColorBrush}" />
        </StackPanel>
    </Border>
    <ControlTemplate.Triggers>
        <Trigger Property="IsSelected"
                    Value="true">
            <Setter Property="TextElement.Foreground"
                    TargetName="ContentSite"
                    Value="{DynamicResource AccentColorBrush}" />
        </Trigger>
        <Trigger Property="IsSelected"
                    Value="false">
            <Setter Property="TextElement.Foreground"
                    TargetName="ContentSite"
                    Value="{DynamicResource GrayNormalBrush}" />
        </Trigger>
        <Trigger SourceName="ContentSite"
                    Property="IsMouseOver"
                    Value="True">
            <Setter Property="TextElement.Foreground"
                    TargetName="ContentSite"
                    Value="{DynamicResource GrayHoverBrush}" />
        </Trigger>
    </ControlTemplate.Triggers>
</ControlTemplate>  

In Mahapps.Metro 1.2.4 it works well, the PART_CloseButton closes the tab.
In the 1.5.0 the close "X" button stops working. When I see the mahapps code I realized, that there is an InternalCloseCommand (internal), which closes the tab.
When I try to bound a new command handler to close the tab manually, I realized that the TabControl.CloseThisTabItem method is internal too.

My question is:
How can I close the tab with close button when I override the template?

Thanks in advance!