`GtkCellRendererCombo` renders text in a cell like `GtkCellRendererText` from which it is derived. But while `GtkCellRendererText` offers
a simple entry to edit the text, `GtkCellRendererCombo` offers a `GtkComboBox` widget to edit the text. The values to display in the
combo box are taken from the tree model specified in the `GtkCellRendererCombo`
model property.
The combo cell renderer takes care of adding a text cell renderer to the combo box and sets it to display the column specified by its
`GtkCellRendererCombo`text_column property. Further properties of
the combo box can be set in a handler for the `GtkCellRenderer:GtkCellRendererCombo:editing-started` signal.