Hello, great library! I am making great use of it!
There is a slight issue with the plot() call to networkx.
In zb.py, around line 833, the script returns a networkx error when setting the parameter of font_size.
# line 833 of zb.py
nx.draw_networkx_edges(newg, pos, edgelist=edgelist, width=1, font_size=8)
The line of code above returns an error like the following:
TypeError: draw_networkx_edges() got an unexpected keyword argument 'font_size'
In my local, simply removing the font_size param from this call results in a successful networkx graph of my knowledge base.
# this works
nx.draw_networkx_edges(newg, pos, edgelist=edgelist, width=1)
I am not 100% sure, but based on the networkx function signature, it seems that the font_size param is not supported for draw edges.