    (labels[i], edge_builder[i], graph.es[i]) for i in range(graph.ecount())
            )
            for label, visual_edge, edge in edge_label_iter:
                # Ask the edge drawer to propose an anchor point for the label
                src, dest = edge.tuple
                src_vertex, dest_vertex = vertex_builder[src], vertex_builder[dest]
                (x, y), (halign, valign) = edge_drawer.get_label_position(
                    visual_edge,
                    src_vertex,
                  