/// <summary>
/// Sets the print handler.
/// </summary>
/// <param name="handler">the new print handler</param>
/// <returns>the old print handler</returns>
public static PrintFunc SetPrintHandler(PrintFunc handler)
{
var helper = new PrintHelper(handler);
var prev = GLib.GSetPrintHandler(helper.Handler);
helper = new PrintHelper(prev);
return(helper.Invoker);
}