class Rubydex::Class

static VALUE rdxr_declaration_visibility(VALUE self) {
    HandleData *data;
    void *graph = rdxi_graph_from_handle(self, &data);

    const CVisibility *visibility = rdx_graph_visibility(graph, data->id);
    if (visibility == NULL) {
        rb_raise(rb_eRuntimeError, "declaration has no visibility");
    }

    VALUE symbol = rdxi_visibility_to_symbol(*visibility);
    free_c_visibility(visibility);

    return symbol;
}