gtk:cell-area-box-pack-start (box renderer &key expand align fixed)

box -- a gtk:cell-area-box widget
renderer -- a gtk:cell-renderer object to add
expand -- a boolean whether renderer should receive extra space when the area receives more than its natural size
align -- a boolean whether renderer should be aligned in adjacent rows
fixed -- a boolean whether renderer should have the same size in all rows

Adds a renderer to the cell area box, packed with reference to the start of the box. The renderer is packed after any other gtk:cell-renderer object packed with reference to the start of the box.