Computation times

00:00.423 total execution time for 3 files from auto_examples/basic:

Example	Time	Mem (MB)
Simple graph (plot_simple_graph.py)	00:00.292	0.0
Properties (plot_properties.py)	00:00.074	0.0
Read and write graphs. (plot_read_write.py)	00:00.057	0.0