IconSource.setSizeWildcarded

If the icon size is wildcarded, this source can be used as the base image for an icon of any size. If the size is not wildcarded, then the size the source applies to should be set with [gtk.icon_source.IconSource.setSize] and the icon source will only be used with that specific size.

#GtkIconSet prefers non-wildcarded sources (exact matches) over wildcarded sources, and will use an exact match when possible.

#GtkIconSet will normally scale wildcarded source images to produce an appropriate icon at a given size, but will not change the size of source images that match exactly.