Adding Python 3 sample to play with mypy and covar specs
Adding Python 3 sample to play with mypy and covar specs

eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog,eliben/code-for-blog