code: func (v *Window) SetStartupID(sid string) {
  	cstr := (*C.gchar)(C.CString(sid))
  	defer C.free(unsafe.Pointer(cstr))
  	C.gtk_window_set_startup_id(v.native(), cstr)
  }
docs: // SetStartupID is a wrapper around gtk_window_set_startup_id().