A `GtkCellRendererPixbuf` can be used to render an image in a cell. It allows to render either a given `GdkPixbuf` (set via the
`GtkCellRendererPixbuf:pixbuf` property) or a named icon (set via the `GtkCellRendererPixbuf:icon-name` property).
To support the tree view, `GtkCellRendererPixbuf` also supports rendering two alternative pixbufs, when the `GtkCellRenderer:is-expander`
property is true. If the `GtkCellRenderer:is-expanded property` is true
and the `GtkCellRendererPixbuf:pixbuf-expander-open` property is set to a pixbuf, it renders that pixbuf, if the
`GtkCellRenderer:is-expanded` property is false and the `GtkCellRendererPixbuf:pixbuf-expander-closed`
property is set to a pixbuf, it renders that one.