code: func (v *Notebook) SetGroupName(groupName string) {
  	cstr := C.CString(groupName)
  	defer C.free(unsafe.Pointer(cstr))
  	C.gtk_notebook_set_group_name(v.native(), (*C.gchar)(cstr))
  }
docs: // SetGroupName() is a wrapper around gtk_notebook_set_group_name().