all_paths seems to repeat identical paths

Hello:

I am new to graph_tool (4 weeks)
Today I attempted to use all_paths to evaluate the strength of connection between classes in a large program.
The output contained (see attached sample) many repetitions of the same path.
What am I missing?

Thanks
JP
(jrpaillet)

attachment.html (1.41 KB)

all_paths_output.txt (1.13 KB)