code: func (v *Window) GetHideTitlebarWhenMaximized() bool {
  	c := C.gtk_window_get_hide_titlebar_when_maximized(v.native())
  	return gobool(c)
  }
docs: // GetHideTitlebarWhenMaximized is a wrapper around
  // gtk_window_get_hide_titlebar_when_maximized().