the edges
    es = graph.es
    if edge_order is None:
        # Default edge order
        edge_coord_iter = zip(es, edge_builder)
    else:
        # Specified edge order
        edge_coord_iter = ((es[i], edge_builder[i]) for i in edge_order)

    # Draw the edges
    if directed:
        drawer_method = edge_drawer.draw_directed_edge
    else:
        drawer_method = edge_drawer.draw_undirected_edge
    for edge, visual_edge in edge_coord_iter:
        src, dest = edge.tuple
        src_vertex, dest_ver