How to set the space size in a toolbar?

[Fernando Conceição <fernando listas terra com br>]

Hi! I´m using gtk 2.2.1.
I read in gtk tutorial( it´s for 2.0) and there I find this function

gtk_toolbar_set_space_size (GTK_TOOLBAR (toolbar), 5);

With this I think I can increase the space that appears whem I use

gtk_toolbar_append_space(GTK_TOOLBAR(toolbar));

But the compiler tells me it´s am implicit declaration(don´t find it on 
.h files) and I look for this on the API for 2.2.1 and it really don´t 
exist any more. So, there is an way to do the same thing
in 2.2.1?
The near I found is "space-size" as a style-propertie, but this is read 
only.

Thanks.