#include <gtk/gtk.h> struct GtkVBox; GtkWidget* gtk_vbox_new (gboolean homogeneous, gint spacing);
GtkVBox is a container that organizes child widgets into a single column.
Use the GtkBox packing interface to determine the arrangement, spacing, height, and alignment of GtkVBox children.
All children are allocated the same width.
a sister class that organizes widgets into a row.