Add a simpler way testing private tasks in step10

[moberhuber]

I'd like to suggest a simpler way testing private tasks, that I came across when working through the tutorial -- simply log out to make private tasks disappear: it's what I had intuitively tried, and wondered about before.

I'd still keep the original method in place as well, for additional insight, so the PR is just a small addition.

[apollo-cla]

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