child to box, packed with reference to the end of box.
The child is packed after (away from end of) any other child
packed with reference to the end of box.gtkBoxPackEnd(object, child, expand = TRUE, fill = TRUE, padding = 0)objectGtkBoxchildGtkWidget to be added to boxexpandTRUE if the new child is to be given extra space allocated
to box. The extra space will be divided evenly between all children
of box that use this optionfillpadding"spacing" property. If child is a widget at one of the
reference ends of box, then padding pixels are also put between
child and the reference edge of box