[graph-tool] how to use vertex_text, etc when using g.save

Hello, I am brand new to graph-tool and found out with example how to label vertices when using graph_draw, as seen below graph_draw(g, vertex_text=labelv, edge_font_size=40, edge_text_distance=20, edge_marker_size=40, output="output.png") but do not see how to label vertices and edges when doing something like: g.save('testoutput.graphml','graphml') Can anyone assist with how this is done? Thanks!