code: func (v *AppChooser) GetContentType() string {
  	cstr := C.gtk_app_chooser_get_content_type(v.native())
  	defer C.free(unsafe.Pointer(cstr))
  	return C.GoString((*C.char)(cstr))
  }
docs: // TODO: Needs gio/GAppInfo implementation first
  // gtk_app_chooser_get_app_info ()
  // GetContentType is a wrapper around gtk_app_chooser_get_content_type().