PowerLine.format.ps1xml

<Configuration>
    <ViewDefinitions>
        <View>
            <Name>PowerLine-Preview</Name>
            <ViewSelectedBy>
                <TypeName>PowerLine.Theme</TypeName>
            </ViewSelectedBy>
            <CustomControl>
                <CustomEntries>
                    <CustomEntry>
                        <CustomItem>
                            <ExpressionBinding>
                                <ScriptBlock>
                                    $CurrentTheme = Get-PowerLineTheme
                                    $_ | Set-PowerLineTheme
                                    $( Write-PowerLinePrompt )
                                    $CurrentTheme | Set-PowerLineTheme
                                </ScriptBlock>
                            </ExpressionBinding>
                        </CustomItem>
                    </CustomEntry>
                </CustomEntries>
            </CustomControl>
        </View>
    </ViewDefinitions>
</Configuration>