Creates a new `PangoLayout` with the appropriate font map, font description, and base direction for drawing text for this widget.
If you keep a `PangoLayout` created in this way around, you need to re-create it when the widget `PangoContext` is replaced. This can be tracked by listening to changes of the [property@Gtk.Widget:root] property on the widget.
text to set on the layout (can be null)
the new `PangoLayout`