the font description to use, or NULL to undo the effect of previous calls to Widget.overrideFont
Deprecated: This function is not useful in the context of CSS-based rendering. If you wish to change the font a widget uses to render its text you should use a custom CSS style, through an application-specific GtkStyleProvider and a CSS style class.
Sets the font to use for a widget. All other style values are left untouched. See Widget.overrideColor.