iface->get_n_pages = impress_document_get_n_pages;
iface->get_page_size = impress_document_get_page_size;
iface->render = impress_document_render;
iface->get_n_pages = impress_document_get_n_pages;
iface->get_page_size = impress_document_get_page_size;
iface->render = impress_document_render;