Returns the underlying #GtkCellArea which might be @cell_layout if called on a #GtkCellArea or might be %NULL if no #GtkCellArea is used by @cell_layout.
the cell area used by @cell_layout, or %NULL in case no cell area is used.
3.0
See Implementation
Returns the underlying #GtkCellArea which might be @cell_layout if called on a #GtkCellArea or might be %NULL if no #GtkCellArea is used by @cell_layout.