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