python new test framework is required. updated in this fork

python: function name should be snake_case

Note that if node 0 is connected to node 1, node 1 is also connected to node 0. This will always be true.

This is not always true. In fact, from the sample tests:

                                      |¯¯¯¯¯¯¯¯¯| where is 1?
                                      v         v
test.assert_equals(isTree([[1,2,3],[0,2],[1,2],[0]]), False)
                              ^           ^^^
                              |____________| where is 0?

The wording is either misleading (if such a case needs to be checked) or otherwise plain wrong.