I've tried the following code:

    simplex.goto("github.com/mitchellh")
    num_contribs = simplex.extract_text("blabla")
    print(num_contribs)

extract_text returns all the lines of text it finds within an element. Looks like for your case it selected a majority of the page from the description, so it's returning most of the text on the page.

We currently don't return failure cases (just closest match) -- but good suggestion! We'll fine tune on some negative cases and see if we can catch them