For clarity, please update your instructions to note that the map is given as a string and not a matrix.

I agree with the other warriors who found the Node objects to be unnecessary.

I think this kata could be improved by completely removing the Node class, changing the test cases to a simple array (list of lists) of 0's and 1's, and changing the solutions to a list of tuples.

Whether underscore is considered alphanumeric (as regex treats it) or not (as we would colloquially treat it) should be clarified in the instructions.